Optimum Nutrition Micronized Creatine Reviews: Ingredients, Price and Side Effects

Optimum Nutrition Micronized Creatine is an unflavored creatine monohydrate powder, and its maker says it is for muscle building support and “intended for daily use by those with serious training and competition goals.” The label lists 5 g of creatine monohydrate per serving, with 60 servings in a 10.58 oz (300 g) container. The product page lists the 60-serving size at a sale price of $20.49, or $0.34 per serving, tax excluded, as of October 28, 2026. Optimum Nutrition offers a 60-day satisfaction guarantee on products bought from optimumnutrition.com or an authorized online seller, plus a Subscribe & Save option at 20% off. Research on creatine is substantial: the NIH Office of Dietary Supplements reports numerous clinical trials generally showing a benefit for high-intensity, intermittent activity, and the ISSN 2017 position stand reports that doses up to 30 g a day for 5 years were safe and well tolerated in healthy people. This page covers the label, price, refunds, side effects, who should check with a clinician first, and how it compares with other creatine products.

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What is Optimum Nutrition Micronized Creatine, and who is it for?

It is a powder you stir into a drink. The product page says it “mixes smooth with only a glass and spoon,” and it can be added to a Gold Standard protein shake. The label says it is intended for healthy adults as part of a healthy, balanced diet and exercise program.

If you want to know how micronized creatine compares with plain monohydrate, our micronized creatine vs monohydrate comparison covers both forms.

What is on the label?

Here are the common label questions, answered from the label and product page:

• Does it have caffeine? No caffeine is listed. The label lists creatine monohydrate and “Other ingredients: None.”
• Does it come with a scoop? The directions call for one rounded teaspoon, and the page says it mixes with only a glass and spoon. Ask customer service what comes in the container if a scoop matters to you.
• Does it use Creapure? The 2021 ISSN paper names AlzChem as the maker of Creapure, so if that brand matters to you, ask the seller before you order.
• Is it gluten free? Ask support to confirm before you order.
• Is it third-party tested? The label says “Banned Substance Tested,” and the brand's graphics say “3rd-party tested.” Ask support which lab ran the testing and whether results are available.
• Is it NSF certified? NSF's NSF Certified for Sport program says certified products are tested for 280+ banned substances. Look for its mark on the label, or ask support whether this tub carries it.

What does the maker say it does?

The product page says the powder “helps enhance muscle strength and growth, maximizes ATP recycling, and accelerates muscle recovery with 5g of creatine monohydrate per serving.” Its benefit list says it “helps build muscle strength and enhance muscle growth,” and those claims carry a footnote reading “when used over time in combination with regular resistance exercise.” The product page also notes that these statements “have not been evaluated by the Food and Drug Administration.”

The brand's pages also say it is America's #1 creatine brand, and that Optimum Nutrition Creatine “took the top spot in a poll of experts by U.S News & World Report for 2026.” The brand cites Euromonitor International for calling itself the world's #1 sports nutrition brand.

For how creatine is supposed to work, Cleveland Clinic explains that most creatine goes to your skeletal muscles, where it becomes phosphocreatine, which helps create ATP, the energy source your cells use when you exercise.

How do you take it, and when?

For the unflavored powder, the label says to “Add one rounded teaspoon to a protein shake or a glass of your favorite beverage. Then mix it up with a spoon.” That is 5 g. For the fruit flavors, add 6 grams to a glass of cold water and stir, mix or blend until dissolved.

The directions name no time of day. The product page calls the powder intended for daily use. If side effects develop, Cleveland Clinic suggests dividing the daily amount into smaller doses taken throughout the day.

The NIH fact sheet gives a loading dose of 20 g a day for up to 7 days, and 3 to 5 g a day for up to 12 weeks, as examples of typical use. The 2021 ISSN paper says a loading phase is not required. This tub's directions use 5 g a day, which sits inside the 3 to 5 g range the NIH lists for maintenance.

What does research say about creatine?

These findings are about creatine monohydrate in general, not about this specific tub.

• NIH Office of Dietary Supplements. Its NIH fact sheet on exercise and athletic performance reports numerous clinical trials generally showing a benefit for high-intensity, intermittent activity, with variation in individual responses. It says creatine may increase strength, power and work from maximal-effort muscle contractions, and that over time it helps the body adapt to athlete training regimens. It also says creatine is of little value for endurance sports.
• ISSN 2017 position stand. The ISSN 2017 position stand says creatine supplementation consistently increases intramuscular creatine concentrations, which may help explain improvements in high-intensity exercise performance. It reports that short- and long-term supplementation, up to 30 g a day for 5 years, is safe and well tolerated in healthy individuals and in a number of patient populations from infants to the elderly. For more on creatine's human studies, safety and side effects, read creatine benefits: human studies, side effects and safety (our research library).
• ISSN 2021 common questions paper. The ISSN 2021 common questions paper says research clearly shows creatine monohydrate to be the optimal choice, though some other forms dissolve more readily in liquid. At recommended doses, it says creatine does not result in kidney damage in healthy individuals. It says creatine may increase water retention in the short term but does not always do so. It says the current research does not indicate increases in total testosterone, free testosterone or DHT, or hair loss; that speculation stems mainly from a single study of college-aged male rugby players. It also says creatine is not an anabolic steroid, and that a loading phase is not required.
• Cleveland Clinic. Its creatine guide says some studies show people who take creatine with regular exercise may gain an extra two to four pounds of muscle over four to 12 weeks compared with people who do not. It says creatine does not affect your ability to exercise for longer periods (aerobic endurance).

The 2021 ISSN paper discloses ties to creatine makers. Several authors report funding, advisory roles or research support from companies that make or sell creatine, including AlzChem, which makes Creapure. The lead author is CEO of the ISSN, an academic non-profit that receives sponsorship from creatine companies.

Is it good, and who gets the most from creatine?

On dose and form, the product lines up with the research above: 5 g a day of creatine monohydrate, within the range the NIH lists for maintenance. Who benefits most depends on the training.

• Strength and power training. The NIH reports benefit for high-intensity, intermittent activity. Cleveland Clinic lists weightlifting, sprinting and bicycling as examples of short, intense exercise.
• Endurance athletes. The NIH says creatine is of little value for endurance sports. If most of your training is long endurance work, that is the finding to weigh.
• Women. The 2021 ISSN paper says there is accumulating research that creatine across the lifespan in females comes with little to no side effects.
• Older adults. The 2021 ISSN paper reports musculoskeletal and performance benefits in older adults, particularly when creatine is combined with exercise. Cleveland Clinic says there is not enough research to say it helps muscle growth in people older than 65.
• Teens. The 2021 ISSN paper calls the research on children and adolescents limited, though it says creatine appears safe and potentially beneficial. The label is written for adults, so check with a clinician first.

How much does it cost, and what is the subscription?

Prices and sizes can change, so check the Product Page for today's price before you buy.

The product page offers two buying options: One-Time Purchase, and Subscribe & Save. Subscribe & Save is marked 20% off, with free delivery on subscription orders. You choose how often it delivers: every 30, 60 (marked most popular), 90, 120 or 150 days. The page says you can “pause, skip or cancel anytime” and lists “no fees.” Before you pay, check which option is selected at checkout, because a subscription repeats at the interval you chose until you pause or cancel it.

The seller's terms say shipping and handling are additional unless the sale says otherwise, and tax is extra.

What are the refund and cancellation terms?

The 60-Day Satisfaction Guarantee lets you request a refund or replacement if you are not satisfied with a product bought from optimumnutrition.com or an authorized online seller. It covers the original end-user purchaser only. To make a claim:

1. Within 60 days of the purchase date, call 1-800-705-5226 or email oncustsuppus@optimumnutrition.com, and tell them where and when you bought it.
2. If your request is approved, mail the product, your proof of purchase and your approval confirmation number to the Consumer Affairs Dept. at the mailing address listed on the guarantee page.
3. Pay the mailing cost yourself, as the guarantee page says you are responsible for it.

The company can verify information, require proof of purchase, and deny requests where it suspects abuse of the guarantee. Keep your receipt and order confirmation.

What are the side effects, and is it safe?

You can report a side effect to the FDA through its Safety Reporting Portal. The FDA's questions and answers on dietary supplements says that under DSHEA, the agency does not have authority to approve dietary supplements before they are marketed, and that manufacturers must follow current good manufacturing practices that help ensure identity, purity, quality, strength and composition.

Who should check with a clinician first?

The label says the product is intended for healthy adults. Cleveland Clinic says a provider will likely ask whether you have diabetes, kidney disease or liver disease, and whether you take any medications, vitamins or other supplements. It recommends talking to a healthcare provider before taking creatine, whatever your fitness level, age or health. If you are looking at creatine because you feel constantly tired, MedlinePlus says that if you have been tired for weeks, you should contact your health care provider, because fatigue can have many different causes.

Is Optimum Nutrition Micronized Creatine legit, or a scam?

The seller's pages name Optimum Nutrition, Inc. as the company behind the product. The product page gives customer service at 1-800-705-5226 and oncustsuppus@optimumnutrition.com. FDA regulations require manufacturers of dietary supplements to follow current good manufacturing practices that help ensure identity, purity, quality, strength and composition, according to the FDA's questions and answers.

Here is what you can check yourself:

• The seller. The guarantee applies only to products bought from optimumnutrition.com or an authorized online seller. The terms say sellers may not sell the products through any Amazon.com marketplace storefront unless Optimum Nutrition approves them. If the seller on your shopping listing is unfamiliar, call or email to ask whether it is authorized before you pay.
• The refund route. Read the 60-day steps above before you order, and keep your receipt and confirmation, since the guarantee requires proof of purchase.
• The claims. The award and brand-ranking statements are the seller's own.

How does it compare with other creatine products?

The seller's lineup includes creatine gummies, creatine capsules, the powder, and Creatine +. The seller's comparison graphic sets plain creatine against Creatine +, which it lists with a vitamin blend and benefit labels such as cellular energy and brain support. Those are the seller's labels, and the powder is the plain-creatine option.

For a side-by-side look at another brand, read the Thorne vs Optimum Nutrition creatine comparison, the Thorne creatine review, or the guide to Crazy Nutrition CRN-5 creatine. Optimum Nutrition's own creatine comparison is covered in optimum nutrition creatine.

Not buying is always an option. The research above ties creatine's documented benefits to high-intensity, intermittent work, so match the choice to your training.

What do buyers say?

The product page shows a 4.5 rating from 460 reviews and a “Best Seller” tag. Those are the seller's own review figures. Read the lowest-rated reviews in the review section yourself before you decide, since an average does not describe each buyer's experience.

Before you order

• Confirm the seller is optimumnutrition.com or an authorized online seller, by calling 1-800-705-5226.
• Choose One-Time Purchase or Subscribe & Save at checkout, and confirm how to pause or cancel.
• Ask support whether this tub carries NSF Certified for Sport and which lab ran the banned-substance testing.
• Ask support whether a scoop is included, and whether the product is gluten free or uses Creapure.
• Keep your receipt and order confirmation, and note the 60-day guarantee window.
• If you have diabetes, kidney disease or liver disease, or take medications, talk to your clinician first.

By the Gym Floor Guide Editorial Team

This article is for general information purposes only and does not constitute medical advice. Consult your doctor or qualified healthcare provider before making changes to your health routine.