Optimum Nutrition vs BulkSupplements Creatine: Which Monohydrate Should You Buy?

The Optimum Nutrition Micronized Creatine and BulkSupplements Creatine Monohydrate are two of the most-reviewed creatines on Amazon, both sitting around 4.6 stars at time of writing. Both are micronized, unflavored creatine monohydrate.

And here’s the thing: monohydrate is monohydrate. The molecule is the same. So this fight comes down to testing, format and price per serving.

Short answer: ON if you want a name-brand tub with banned-substance testing and zero hassle. BulkSupplements if you want the most creatine for the least money.

Head-to-head specs

Specs per the manufacturers and listings at time of writing.

Round 1: What’s inside — Tie

Both are plain micronized creatine monohydrate with nothing else added. Your muscles can’t read the label. Call it even.

Round 2: Testing and peace of mind — ON wins

ON’s creatine is banned-substance tested and part of the Informed Choice program. That’s a clear, third-party answer to “is this actually what it says?” If testing matters to you, ON has the easier story to trust.

Round 3: Daily convenience — ON wins

A tub with a scoop beats digging around a floppy pouch at 6am. ON’s 5g serving is one scoop, done. Pouches work fine, but they’re messier and you’ll probably want your own scoop.

Round 4: Price per gram — BulkSupplements wins

This is BulkSupplements’ whole reason to exist. Plain packaging, bigger bags, and typically a lower cost per gram. If you’re taking creatine for years, that adds up.

Round 5: Buying in bulk — BulkSupplements wins

Want a bag that lasts most of a year? BulkSupplements sells larger sizes than ON’s tub. Fewer reorders, better value, more room in your cabinet for protein.

Get the ON tub   Check BulkSupplements price

How to take either one

• 3–5g a day, every day. Consistency beats timing.
• Loading is optional. Daily 3–5g gets you to the same place, just a bit slower.
• Drink water. Stay hydrated.
• Check with your doctor first, especially if you have kidney issues, any medical condition, or you’re on medication.

Who should buy which

Buy ON if… you want a trusted brand with banned-substance testing, a proper tub and scoop, and a fair price for four months of creatine.

Buy BulkSupplements if… you’re a price-per-gram guy, you want a giant bag, and you don’t care what it looks like on the shelf.

The verdict

Call it a 2–2 split with a tie, and ON takes it on the tiebreaker: testing. Same creatine, but ON’s Informed Choice testing and easy tub make it the better pick for most guys. If saving every cent matters more, BulkSupplements is a great value.

See the full lineup in our 10 best creatine supplements, or read why ON Creatine is a must-have.