# Best Bulk Protein Powder > The best bulk protein powder on Amazon: 5 to 10 lb bags and tubs ranked on cost per 25 g at scale, testing and shelf life, plus how to store a big bag. - **URL**: https://www.best-proteinpowder.com/best-bulk-protein-powder/ - **Updated**: 2026-11-09 - **Author**: [Best Protein Powder Editorial Team](https://www.best-proteinpowder.com/authors/editorial-team/) - **Publisher**: [Best Protein Powder](https://www.best-proteinpowder.com/) --- Seven 5 to 10 lb powders ranked on cost per 25 g of protein at full size, certification, ingredients and how well they keep, plus the storage and shelf-life rules that decide whether a big bag actually saves money. **How we rank:** We judge every powder on the label, not the marketing: protein per scoop, cost per 25 g of protein, the full ingredient list and third-party testing. No paid placements, and commission never sets a ranking. [Read our methodology](https://www.best-proteinpowder.com/how-we-test/) The best bulk protein powder for most people is **Optimum Nutrition Gold Standard 100% Whey in the 10 lb size**: about 149 servings of 24 g each per retailer listings, Informed Choice promotion from the brand, dozens of flavors and a cost per 25 g that drops well below the small tubs, especially on sale. If you want one ingredient and no sweetener, Naked Whey's 5 lb bag is the pick, and Naked Pea is the bulk plant option. ## Our Top Picks | Award | Product | Why | | --- | --- | --- | | Best Overall Bulk Powder | [Optimum Nutrition Gold Standard 100% Whey](https://www.best-proteinpowder.com/best-bulk-protein-powder/#optimum-nutrition-gold-standard-100-whey) | The safest big-tub buy: tested, widely liked and cheap per gram whenever it is on sale. | | Best One-Ingredient Bulk Whey | [Naked Whey (Unflavored)](https://www.best-proteinpowder.com/best-bulk-protein-powder/#naked-nutrition-naked-whey) | The best bulk pick for people who cook and blend with their protein and want nothing else in it. | | Best Bulk Isolate | [NOW Sports Whey Protein Isolate (Unflavored)](https://www.best-proteinpowder.com/best-bulk-protein-powder/#now-sports-whey-protein-isolate) | The bulk choice if you want isolate for lactose or macros without paying premium-brand prices. | | Best Budget Bulk Whey | [Nutricost Whey Protein Concentrate](https://www.best-proteinpowder.com/best-bulk-protein-powder/#nutricost-whey-protein-concentrate) | The cheapest branded bulk whey that still discloses a full label and claims third-party testing. | | Best for Sale Shoppers | [Myprotein Impact Whey Protein](https://www.best-proteinpowder.com/best-bulk-protein-powder/#myprotein-impact-whey-protein) | Excellent bulk value if you wait for a sale, and only average if you do not. | | Best Premium Bulk Isolate | [Dymatize ISO100 Hydrolyzed Whey Protein Isolate](https://www.best-proteinpowder.com/best-bulk-protein-powder/#wpi-dymatize-iso100) | The bulk isolate for people who will pay more per shake for macros and mixability. | | Best Bulk Plant Protein | [Naked Pea Protein](https://www.best-proteinpowder.com/best-bulk-protein-powder/#naked-nutrition-naked-pea) | The plant protein to buy in bulk, ideally after checking the brand's latest batch test. | ## 1. Quick Comparison: The Best Bulk Protein Powders The short version: Optimum Nutrition Gold Standard in 10 lb is the best bulk buy for most people, Naked Whey's 5 lb bag is the best one-ingredient option, Nutricost is the cheapest branded whey, Myprotein is the best value when it is on sale, and Naked Pea is the bulk plant protein. Bulk only saves money if you finish the bag while it still tastes good, so size matters as much as brand. All figures below are per the label or retailer listing at the time of writing and vary by flavor. | Product | Protein per serving | Largest size | Best for | | --- | --- | --- | --- | | Optimum Nutrition Gold Standard | About 24 g | 10 lb, about 149 servings | Most bulk buyers | | Naked Whey | About 25 g | 5 lb bag | One ingredient, no sweetener | | NOW Sports Whey Isolate | 24 g | 5 lb unflavored; 10 lb flavored | Bulk isolate | | Nutricost Whey Concentrate | 25 g | 5 lb | Lowest cost per shake | | Myprotein Impact Whey | About 19-22 g | 5.5 lb, about 130 servings | Sale shoppers | | Dymatize ISO100 | About 25 g | 5 lb | Premium isolate | | Naked Pea | About 27 g | 5 lb bag | Plant-based | A rule of thumb before you add a 10 lb tub to the cart: one scoop a day gets through 10 lb of whey in about five months, and two scoops a day in about ten weeks. Both are comfortably inside a typical best-by window. Half a scoop every other day is not, and that is when a bulk bag stops being a bargain. ## 2. The Best Bulk Protein Powders, Ranked These seven are ranked on cost per 25 g of protein at their largest common size, third-party certification, ingredient quality, how many servings the big size holds and how practical it is to store. We did not buy and lab-test these powders; picks rest on labels, certifier databases and published research, and taste notes are buyer reports. See [how we test](https://www.best-proteinpowder.com/how-we-test/) for the method. Figures are per the label at the time of writing and vary by flavor. ### 1. Optimum Nutrition Gold Standard 100% Whey **Award:** Best Overall Bulk Powder | **Type:** Whey isolate, concentrate and peptide blend - **Protein / serving:** About 24 g (label) - **Largest size:** 10 lb, about 149 servings - **Cost per 25 g tier:** Budget to mid at 10 lb - **Best for:** Most people buying in bulk Gold Standard is the default bulk whey for good reason. The 10 lb tub holds about 149 servings per retailer listings, and per the label at the time of writing each roughly 30 g scoop gives about 24 g of protein in around 120 calories. Optimum Nutrition promotes it as Informed Choice certified. At 10 lb the cost per 25 g falls well below the 2 lb tub, and on sale it competes with budget brands. It comes in more flavors in the big size than almost anyone else. **Bottom line:** The safest big-tub buy: tested, widely liked and cheap per gram whenever it is on sale. **Pros:** - About 149 servings in the 10 lb size, per retailer listings - Promoted as Informed Choice certified by the brand - Wide flavor choice even in the largest tub **Cons:** - List price on the 10 lb is high; the value depends on catching a sale - Contains concentrate, so more lactose than an isolate - Heavily counterfeited brand, so buy from Amazon or ON's storefront [Check price on Amazon](https://www.amazon.com/dp/B000GISTZ4?tag=sktiger-20&linkCode=ll1) ### 2. Naked Whey (Unflavored) **Award:** Best One-Ingredient Bulk Whey | **Type:** Unflavored grass-fed whey concentrate - **Protein / serving:** About 25 g (label) - **Largest size:** 5 lb bag - **Cost per 25 g tier:** Budget to mid - **Best for:** Smoothies, baking, no sweetener Naked Whey has one ingredient, whey protein concentrate from grass-fed cows that the brand says come from US farms, and it is sold in a 5 lb bag. Per the label at the time of writing it gives about 25 g of protein in roughly 120 calories per serving, with no sweetener or flavor. Unflavored suits bulk buying better than any flavor, because you will not get tired of it: flavor it differently in smoothies, oats, coffee or baking. It does not carry a sport certification we could confirm. **Bottom line:** The best bulk pick for people who cook and blend with their protein and want nothing else in it. **Pros:** - Single ingredient with no sweeteners or flavors - Unflavored avoids flavor fatigue across a 5 lb bag - About 25 g of protein per serving per the label **Cons:** - No sport certification we could confirm - Bland on its own in water - Resealable bag is less sturdy than a tub for daily scooping [Check price on Amazon](https://www.amazon.com/dp/B00XIKPUK4?tag=sktiger-20&linkCode=ll1) ### 3. NOW Sports Whey Protein Isolate (Unflavored) **Award:** Best Bulk Isolate | **Type:** Whey protein isolate - **Protein / serving:** 24 g (label) - **Largest size:** 5 lb unflavored; 10 lb flavored - **Cost per 25 g tier:** Mid - **Best for:** Lactose-sensitive bulk buyers NOW Sports Whey Isolate is the value isolate for bulk buyers. The unflavored 5 lb tub lists 24 g of protein in 110 calories per 28 g scoop, with about 1 g of carbohydrate and no sweetener, per the label at the time of writing, and flavored versions are listed in 10 lb sizes. Isolate keeps a little better than concentrate because it has less fat and lactose. NOW lists Informed Sport on the label; check the certifier's database for the exact product and size you buy. **Bottom line:** The bulk choice if you want isolate for lactose or macros without paying premium-brand prices. **Pros:** - 24 g of protein in 110 calories per scoop, per the label - Isolate with very little lactose or fat - Unflavored 5 lb and flavored 10 lb sizes **Cons:** - Unflavored tastes faintly milky on its own - Costs more per 25 g than concentrates - Flavored 10 lb tubs are a big commitment to one flavor [Check price on Amazon](https://www.amazon.com/dp/B0013OWAB4?tag=sktiger-20&linkCode=ll1) ### 4. Nutricost Whey Protein Concentrate **Award:** Best Budget Bulk Whey | **Type:** Whey protein concentrate - **Protein / serving:** 25 g (listing) - **Largest size:** 5 lb - **Cost per 25 g tier:** Budget - **Best for:** Lowest cost per shake Nutricost is a value brand with a large Amazon presence, and its 5 lb whey concentrate is one of the lowest-cost ways to buy a branded whey in bulk. Retailer listings for the milk chocolate concentrate show 25 g of protein per 36 g scoop and about 130 to 140 calories. Nutricost says its products are third-party tested and made in a GMP-compliant facility, though listings do not name the lab. Unflavored and grass-fed versions are also sold. **Bottom line:** The cheapest branded bulk whey that still discloses a full label and claims third-party testing. **Pros:** - Budget cost per 25 g in the 5 lb size - 25 g of protein per scoop per retailer listings - Unflavored and grass-fed variations available **Cons:** - Third-party testing is a brand claim, with no named lab - No sport certification we could confirm - Larger scoop and more calories per gram of protein than an isolate [Check price on Amazon](https://www.amazon.com/dp/B01KITQDK8?tag=sktiger-20&linkCode=ll1) ### 5. Myprotein Impact Whey Protein **Award:** Best for Sale Shoppers | **Type:** Whey protein concentrate - **Protein / serving:** About 19-22 g by flavor (listing) - **Largest size:** 5.5 lb, about 130 servings - **Cost per 25 g tier:** Budget on sale; mid at list - **Best for:** Buyers who stock up on sales Myprotein's US listing gives about 19 to 22 g of protein per 25 g scoop depending on flavor, at around 100 calories, with a 5.5 lb size of about 130 servings. Its list price is not cheap, but the brand runs frequent sales of up to half off, and at those prices the cost per 25 g drops into the budget tier. The brand promotes Informed Choice and Informed Protein certification. It comes in a very long flavor list. **Bottom line:** Excellent bulk value if you wait for a sale, and only average if you do not. **Pros:** - About 130 servings in the 5.5 lb size - Frequent deep sales bring cost per 25 g into the budget tier - Promoted as Informed Choice and Informed Protein certified **Cons:** - Smaller scoop means fewer grams of protein per serving - Protein per scoop varies noticeably by flavor - Poor value at full list price [Check price on Amazon](https://www.amazon.com/dp/B0H5L6C9VL?tag=sktiger-20&linkCode=ll1) ### 6. Dymatize ISO100 Hydrolyzed Whey Protein Isolate **Award:** Best Premium Bulk Isolate | **Type:** Hydrolyzed whey isolate - **Protein / serving:** About 25 g (label) - **Largest size:** 5 lb - **Cost per 25 g tier:** Mid-premium - **Best for:** Lean macros, lactose sensitivity ISO100 is the default premium isolate, and the 5 lb tub is the size where its cost per gram becomes reasonable. It gives about 25 g of protein per scoop from hydrolyzed whey isolate and whey isolate, with very little fat or carbohydrate, per the label at the time of writing. It is promoted as Informed Choice certified, and buyers widely report that it mixes thin and clean in water. It keeps well in a tub because the low fat content slows staling. **Bottom line:** The bulk isolate for people who will pay more per shake for macros and mixability. **Pros:** - About 25 g of protein per scoop with minimal fat and carbs - Promoted as Informed Choice certified - Buyers consistently report clean mixing and good flavors **Cons:** - Premium price even at 5 lb - Hydrolyzed isolate is overkill for many people - Popular flavors sell out in the big size [Check price on Amazon](https://www.amazon.com/dp/B099J2SWXV?tag=sktiger-20&linkCode=ll1) ### 7. Naked Pea Protein **Award:** Best Bulk Plant Protein | **Type:** Unflavored pea protein - **Protein / serving:** About 27 g (label) - **Largest size:** 5 lb bag - **Cost per 25 g tier:** Budget - **Best for:** Vegan and dairy-free bulk buyers Naked Pea is the plant counterpart to Naked Whey: one ingredient, yellow pea protein, which the brand says comes from the United States and Canada, sold in a 5 lb bag. It delivers about 27 g of protein in roughly 120 calories per serving per the label at the time of writing, at a budget-tier cost per 25 g. Like any plant protein it carries a higher average heavy-metal risk than whey, so ask the brand for current batch results before committing to a big bag. **Bottom line:** The plant protein to buy in bulk, ideally after checking the brand's latest batch test. **Pros:** - About 27 g of protein per serving per the label - Single ingredient, unflavored and unsweetened - Budget-tier cost per 25 g in the 5 lb bag **Cons:** - Earthy taste and gritty texture in a shaker - Plant proteins carry higher average heavy-metal levels than whey - No sport certification we could confirm [Check price on Amazon](https://www.amazon.com/dp/B00NBIUGA2?tag=sktiger-20&linkCode=ll1) ## 3. Is Buying Protein Powder in Bulk Cheaper? Cost per 25 g at Scale Usually, yes, but by less than the tub size suggests and not always. The fixed costs of a protein tub, the container, label, shipping weight and retail margin, are spread over more servings in a big size, so cost per gram of protein normally falls as size rises. Moving from a 2 lb tub to a 5 lb tub of the same powder typically lowers cost per 25 g of protein, and moving to 10 lb usually takes off a little more, but the size of the saving varies by brand and flavor and moves with every sale. The only fair comparison is cost per 25 g of protein. Price per pound misleads, because powders differ in how much of each scoop is protein, and price per serving misleads because scoop sizes range from about 25 g to 45 g. Take the price, divide by the number of servings, divide by the protein per serving and multiply by 25. Using Optimum Nutrition's 10 lb Gold Standard as an example, a retailer list price we saw of about $170 for 149 servings of 24 g works out to about $1.19 per 25 g; a sale price we saw of about $133 brings it to about $0.93. | Example (illustrative) | Price | Servings x protein | Cost per 25 g | | --- | --- | --- | --- | | 10 lb whey at list price | About $170 | 149 x 24 g | About $1.19 | | Same 10 lb tub on sale | About $133 | 149 x 24 g | About $0.93 | | Your 5 lb tub | Listing price | Servings x protein (label) | Price / servings / protein x 25 | | Your 2 lb tub | Listing price | Servings x protein (label) | Usually higher than 5 lb | The catch is that the size with the lowest list price per gram is not always the cheapest to buy. Sales and coupons on Amazon are often applied to the popular 5 lb size and not to the 10 lb, and a 5 lb tub at 25 percent off can beat a 10 lb tub at full price. Check the cost per 25 g of the sizes you are deciding between on the day, and use our [protein cost calculator](https://www.best-proteinpowder.com/tools/protein-cost-calculator/) rather than assuming the bigger box wins. Bulk also changes what is worth paying for. A tested, mid-priced whey in a 10 lb size often costs about the same per 25 g as an untested budget powder in a 2 lb tub, which makes the case for buying the better product in a bigger size. Our [best cheap protein powder](https://www.best-proteinpowder.com/best-cheap-protein-powder/) guide covers the lowest cost per 25 g at regular sizes, and our [best Costco protein powder](https://www.best-proteinpowder.com/best-costco-protein-powder/) guide covers warehouse-club pricing, which is the main competitor to buying bulk on Amazon. ## 4. How Long Does Protein Powder Last? Shelf Life and Expiration Dates Longer than most people fear, but not forever. Most whey powders carry a best-by date roughly one to two years after manufacture, and most of that window has usually passed before the tub reaches you. A best-by date is a quality date, not a safety cliff. Dry protein powder has too little water for bacteria to grow, so the realistic risks of an old tub are flavor, texture and a slow loss of quality rather than food poisoning, provided it has stayed dry. The best published data comes from a USDA study by Tunick and colleagues in the Journal of Dairy Science in 2016, which stored whey protein concentrate in sealed bags at different temperatures and humidity. It estimated a shelf life of about 9 months at 35 degrees Celsius, about 95 degrees Fahrenheit, but at least 18 months at lower temperatures. The warm samples yellowed and developed off-flavors as fats oxidized and proteins reacted with lactose. Cool storage roughly doubled the useful life. That reaction between protein and lactose, the Maillard reaction, also slowly reduces the availability of lysine, an essential amino acid. It is the main nutritional cost of old or hot-stored powder, and it is one reason isolates, with less lactose, tend to keep a little better than concentrates. Flavored powders can also lose sweetness and flavor intensity before the protein itself changes much. In practice: buy a size you will finish well inside the best-by date, store it cool and dry, and judge an older tub by smell, color and clumping. A powder that smells rancid, cardboard-like or sour, has darkened or yellowed, or has turned into hard clumps should go. Hard clumping means moisture got in, and moisture is the one condition under which mold or bacteria can grow. If you are uncertain, throw it out; a few dollars of powder is not worth a stomach upset. ## 5. How to Store a 5 or 10 lb Bag of Protein Powder Storage decides whether a bulk bag stays good to the last scoop. The enemies are heat, humidity and air. Every time you open the container you let in humid air, and in a warm kitchen that is enough to start clumping and staling within months. The fixes are simple and cost nothing. ### Keep it cool, dry and dark Store the tub or bag in a cupboard away from the stove, dishwasher and sunny windows. Do not keep it in a hot car or garage; the Tunick data shows warm storage can roughly halve shelf life. The refrigerator is not a good idea either: taking a cold tub out into a warm kitchen causes condensation inside, which is exactly the moisture you are trying to avoid. ### Decant a big bag A 10 lb tub or 5 lb bag opened every day lets in a lot of air. The better approach is to keep a small working container, an old 2 lb tub or an airtight canister, and refill it every week or two from the big bag, which you then squeeze the air out of and seal. The bulk of the powder stays sealed and dry, and only the working container is exposed. Leave the desiccant packet in the big bag, and use a dry scoop every time. ### Bags vs tubs Resealable bags, like Naked's, take less space and can be pressed flat to push air out, but their zippers fail with heavy daily use and powder gets in the seal. Tubs are sturdier and easier to scoop from but leave a lot of air above the powder as it empties. For 10 lb sizes, a tub is easier to live with; for 5 lb bags, decanting into a tub or canister solves the zipper problem. Write the best-by date and the date you opened it on the lid. ## 6. 5 lb vs 10 lb: Which Size Should You Buy? For most people the 5 lb size is the sweet spot. It captures most of the per-gram saving of buying bulk, it lasts about two to two and a half months at one scoop a day, and it is small enough to buy in a different flavor next time. A 10 lb tub makes sense if you take two scoops a day, share the tub with a partner or teenager, or already know you like the flavor. Work out your burn rate before deciding. Divide the servings in the tub by the scoops you actually take per day, not the number you intend to take. A 149-serving tub at one scoop a day lasts about five months; at a scoop every other day it lasts ten months, and the last few months will be noticeably staler. If your realistic rate means you will not finish the tub in six to nine months, buy smaller. Flavor fatigue is the other reason bulk bags get abandoned. A flavor you like in a 2 lb tub can become hard to face after 140 servings. Buy a small tub or single-serve packets of a flavor before committing to 10 lb of it; our [best protein powder packets](https://www.best-proteinpowder.com/best-protein-powder-packets/) guide covers sample sizes. Unflavored bulk powder avoids the problem entirely, because you change the flavor every time you use it. Finally, think about how you will use it. If most of your protein goes into smoothies, oats or baking rather than a shaker, a bulk unflavored whey is ideal, and it is the cheapest way to make the homemade protein pancakes in our sibling guide to the [best protein pancake mix](https://www.best-proteinpowder.com/best-protein-pancake-mix/). Check our [how much protein do I need](https://www.best-proteinpowder.com/how-much-protein-do-i-need/) guide too: many people need fewer scoops than they think, which changes the size that makes sense. ## 7. Bulk Flavored, Unflavored or Plant Protein? Unflavored whey is the best fit for bulk buying. It is usually the cheapest version of any powder, it keeps at least as well as flavored versions, and it avoids flavor fatigue because you flavor it differently every time. It is also the easiest to use in cooking. The drawback is that unflavored whey in water tastes like thin milk, so it needs a smoothie, oats, coffee or a dash of cocoa to be pleasant. Our [best unflavored protein powder](https://www.best-proteinpowder.com/best-unflavored-protein-powder/) guide covers more options. Whey concentrate or isolate? Concentrate is cheaper per 25 g and is the backbone of most bulk powders, including Gold Standard's blend, Naked Whey and Nutricost. Isolate costs more but has less lactose and fat, which helps people with mild lactose intolerance and slightly extends shelf life. If concentrate gives you no trouble, buy concentrate in bulk; our [whey vs whey isolate](https://www.best-proteinpowder.com/whey-vs-whey-isolate/) guide explains the trade-off, and the [best whey protein isolate](https://www.best-proteinpowder.com/best-whey-protein-isolate/) rankings cover isolates at regular sizes. Plant protein in bulk deserves more caution. Pea, rice and other plant proteins tend to carry more lead and cadmium than whey because plants absorb them from soil, and a 5 lb bag is a big commitment to one batch. Before you buy a bulk plant powder, look for the brand's batch heavy-metal test results or a certification that covers contaminants, and read our [best protein powder without heavy metals](https://www.best-proteinpowder.com/best-protein-powder-without-heavy-metals/) guide. If you are pregnant or buying for children, ask a doctor or registered dietitian before relying on a single plant powder daily. Collagen, casein and egg white are sold in bulk too, but they suit narrower uses. Casein for a nightly shake is worth buying in a bigger size if you already know you like it; collagen is an incomplete protein and a poor value per gram of usable protein in bulk. ## 8. Buying Bulk Protein Powder on Amazon: Sellers, Dates and Size Traps Big tubs are where Amazon's protein risks are most expensive. A counterfeit or stale 10 lb tub costs far more than a bad 2 lb tub, and big sizes are more likely to sit in a warehouse. These checks are specific to buying in bulk. ### Buy from the brand or Amazon, not a stranger Check the line under the Add to Cart button: shipped from and sold by Amazon, or by the brand's own storefront, is what you want. High-price items such as 10 lb tubs of popular brands attract third-party resellers and, occasionally, counterfeiters. A 10 lb tub priced well below every other listing is a warning sign. When the tub arrives, check that the seal under the lid is intact and the printing looks crisp, and compare the lot code format with the brand's other products. ### Check the lot and best-by dates on arrival Big sizes sell more slowly, so they are more likely to arrive with less shelf life left. Look at the best-by date the day it arrives and compare it with how long you need to finish the tub. If a 10 lb tub that will take you five months has four months left, return it or contact the seller. Amazon listings cannot promise a date, so this check is on you. ### Watch size and flavor variations Bulk protein listings bundle 2, 5 and 10 lb sizes and dozens of flavors as variations of one page, and the price shown in search results is often for a different size or flavor than the one you clicked. Confirm the size and serving count in the title and on the label image before checkout. Large sizes in less popular flavors can be priced higher per pound than the same flavor in 5 lb, the reverse of what you would expect. ### Read the label image and work out cost per 25 g Bullet copy is often written for the whole product family and can be out of date. The nutrition panel image is more reliable, especially for protein per scoop, which can differ between flavors and between the 5 lb and 10 lb versions. Use it to calculate cost per 25 g of protein from the listing price. Subscribe & Save typically takes 5% off, and up to 15% when you have five or more subscriptions in one delivery, and on a 10 lb tub that is a meaningful saving. Set the delivery interval to match your real burn rate so a second tub does not arrive before the first is finished. Our [Amazon protein powder](https://www.best-proteinpowder.com/amazon-protein-powder/) guide covers the platform in more detail. ## 9. How We Picked We ranked these powders on cost per 25 g of protein at their largest common size, published third-party certification, ingredient quality, servings per container and practical storage. We did not buy and test the powders ourselves; picks rest on labels, certifier databases, retailer listings and published research such as the Tunick shelf-life study, and taste notes reflect buyer reports. Prices and certifications change, so confirm them on the day. If you want something different in your big tub, our sibling guides to the [best all-in-one protein powder](https://www.best-proteinpowder.com/best-all-in-one-protein-powder/) and the [best protein shaker bottle](https://www.best-proteinpowder.com/best-protein-shaker-bottle/) cover what to mix and what to mix it in. ## 10. Common Mistakes to Avoid ### Assuming the biggest tub is always cheapest Sales and coupons often apply to the 5 lb size, not the 10 lb, and some flavors cost more per pound in bigger sizes. Calculate cost per 25 g of protein for each size on the day you buy instead of assuming bigger means cheaper. ### Buying more than you will finish Work out how many scoops you really take per day. If a tub will last longer than six to nine months at that rate, the end of it will be stale. A 5 lb tub you finish beats a 10 lb tub you throw half of away. ### Storing a big bag somewhere warm Research on whey concentrate found shelf life fell to about 9 months at 35 degrees Celsius, versus at least 18 months at lower temperatures. Keep bulk powder in a cool cupboard, never a hot garage or car, and not in the fridge. ### Scooping straight from the bulk bag every day Every opening lets humid air in. Keep a small working container and refill it every week or two, sealing the big bag with the air pressed out and the desiccant left inside. Always use a dry scoop. ### Committing to a new flavor in 10 lb Flavor fatigue is the most common reason bulk tubs get abandoned. Try a small tub or sample packets first, or buy unflavored and flavor it yourself. Bulk only saves money if you enjoy the last scoop as much as the first. ## 11. Frequently Asked Questions ### What is the best bulk protein powder? For most people, Optimum Nutrition Gold Standard 100% Whey in the 10 lb size is the best bulk protein powder: about 149 servings of 24 g per retailer listings, promoted as Informed Choice certified, and low cost per 25 g on sale. Naked Whey is the best one-ingredient bulk whey, and Naked Pea is the best bulk plant protein. ### Is it cheaper to buy protein powder in bulk? Usually. Moving from a 2 lb to a 5 lb tub of the same powder typically lowers cost per 25 g of protein, and 10 lb often saves a little more, though the saving varies by brand. But sales often apply to specific sizes, so a discounted 5 lb tub can beat a full-price 10 lb. Compare cost per 25 g on the day. ### How long does a 10 lb tub of protein last? About 149 servings means about five months at one scoop a day and about ten weeks at two scoops a day. That fits inside typical best-by dates if you store the tub cool and dry. At a scoop every other day it lasts about ten months, which is long enough for flavor and quality to decline. ### Does protein powder expire? It carries a best-by date, usually about one to two years after manufacture, which is about quality rather than safety. A USDA study found whey concentrate kept at least 18 months at moderate temperatures but only about 9 months at 35 degrees Celsius. Discard powder that smells off, has changed color or has hardened into clumps. ### How should I store bulk protein powder? Keep it sealed in a cool, dry, dark cupboard, away from the stove and sunny windows, and not in a car, garage or refrigerator. Decant a week or two at a time into a small working container so the bulk bag stays sealed. Keep the desiccant packet in and always use a dry scoop. ### Should I buy bulk whey concentrate or isolate? Buy concentrate if dairy does not bother you; it is cheaper per 25 g and is what most bulk powders use. Choose isolate if you are mildly lactose intolerant or want fewer carbs and fat, and expect to pay more. Isolate's lower lactose and fat also help it keep slightly better over a long tub. ### Is bulk plant protein safe? Plant proteins tend to carry more lead and cadmium than whey because plants absorb them from soil, so check a bulk plant powder's batch heavy-metal results or contaminant certification before buying a big bag. If you are pregnant, buying for a child or have a medical condition, ask a doctor or registered dietitian before relying on one daily. ## Related Protein Powder Guides - [Best Cheap Protein Powder](https://www.best-proteinpowder.com/best-cheap-protein-powder/): The lowest cost per 25 g of protein at regular tub sizes. - [Best Costco Protein Powder](https://www.best-proteinpowder.com/best-costco-protein-powder/): Warehouse-club bulk tubs, compared on price and testing. - [Best Protein Shaker Bottle](https://www.best-proteinpowder.com/best-protein-shaker-bottle/): The bottles that mix your bulk powder cleanly and do not leak. ## The Bottom Line Optimum Nutrition Gold Standard in 10 lb is the best bulk protein powder for most people: tested, widely liked and cheap per 25 g whenever it is on sale. Naked Whey is the one-ingredient pick, NOW Sports the bulk isolate, Nutricost the budget whey, Myprotein the sale buy and Naked Pea the plant option. Compare cost per 25 g of protein on the day, not price per pound. Bulk only saves money if you finish the bag while it is still good. Pick a size that matches how many scoops you really take, store it cool and dry, decant it into a small working container, and check the best-by date the day it arrives. Do that, and a big bag is the simplest way to cut what you spend on protein without buying a worse product. ## More in Protein Powder Guides in this category that pair with what you just read. - [Amazon Protein Powder](https://www.best-proteinpowder.com/amazon-protein-powder/) - [Best Whey Protein Powder](https://www.best-proteinpowder.com/best-whey-protein-powder/) - [Best Whey Protein Concentrate](https://www.best-proteinpowder.com/best-whey-protein-concentrate/) - [Best Unflavored Protein Powder](https://www.best-proteinpowder.com/best-unflavored-protein-powder/) - [Best Protein Pancake Mix](https://www.best-proteinpowder.com/best-protein-pancake-mix/) About the Author [Best Protein Powder Editorial Team](https://www.best-proteinpowder.com/authors/editorial-team/), Supplements Desk The editorial team reads the label, the certificate and the price per gram of protein before a powder gets near a ranking -- and says plainly when a cheaper tub does the same job. [Full profile](https://www.best-proteinpowder.com/authors/editorial-team/) | [How we test](https://www.best-proteinpowder.com/how-we-test/)