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Vitamin U S-methylmethionine 500 mg supplement bottle
Vitamin U S-methylmethionine 500 mg supplement bottle
Vitamin U capsule, 500 mg S-methylmethionine
Supplement facts panel: 500 mg S-methylmethionine per capsule, 60 capsules

S-methylmethionine

Vitamin U, 500 mg

S-methylmethionine is the active compound in cabbage juice. One active ingredient, 60 capsules.

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30-day money-back
3rd-party lab tested
Vegan capsule

S-methylmethionine, Vitamin U or SMM, is a vitamin-like compound found in raw cruciferous vegetables such as cabbage, broccoli and kale. Raw cabbage juice is the most concentrated food source.

Supports the stomach's natural mucus layer.*
Helps maintain stomach comfort.*
Acts as a methyl donor and antioxidant for everyday health.*

Take 1 capsule once or twice daily with food, or as directed by your healthcare professional.

About the smell: vitamin U is a sulfur compound, so the bottle has a cabbage-like smell. If you notice it, that is the ingredient doing its job, and you got the real thing.

VitaminYOU is manufactured with our customers in mind. Manufactured in the USA with globally sourced ingredients, in cGMP-compliant facilities. Every batch is tested by an independent lab here in the US. If you are not 100% satisfied, we offer a 30-day money-back guarantee.

Read the full FAQ
Manufactured in the USA
With globally sourced ingredients, in a registered facility.
cGMP compliant
Made to Good Manufacturing Practice standards for consistency and safety.
3rd-party lab tested
Every batch tested for purity and potency by an independent lab in the US.
30-day money-back guarantee
Not satisfied for any reason? Contact us within 30 days for a full refund.

The ingredient

All the active compound. None of the cabbage juice.

S-methylmethionine is the active compound in raw cabbage juice. When people drink it for their stomach, Vitamin U is what they're getting. Cabbage contains 53 to 104 mg per 100 g,2 so reaching 500 mg means drinking about a liter.

500 mg
per capsule
1 liter
of cabbage juice to match it2
Before and after illustration: a thin mucus layer with acid reaching the stomach lining, then a thicker mucus layer with vitamin U in it and less acid reaching the lining

Why vitamin U

What it does for your stomach.

1
Supports the stomach's natural mucus layer.*1
2
Gentle on your stomach. Cabbage juice brings fiber, gas and goitrogens.
3
One capsule, 500 mg, about a liter of cabbage juice.
Nadya, founder of VitaminYOU

Founded by someone who uses it

"I hope it works for you the way it works for me. I still take it every day."

Nadya, certified nutritionist, founder · Read her story

Learn more

Do your own research.

The ingredient S-methylmethionine, explained What Vitamin U is, where it comes from, and why the name stuck. Read the article The research Global Vitamin U Research Database Every study we could find, from 1949 to today, with the source named so you can check it yourself. Open the database The blog Everything about the stomach Dosage, how long it takes, what to eat, how it compares to other supplements. Plain language, sources named. Browse the blog

FAQ

Questions.

See all FAQs

Still have one? Shoot us a message and we reply within one business day.

No. Vitamins are nutrients your body can't make and has to get from food. S-methylmethionine doesn't meet that definition. The name came from 1950s research and never went away.
It's the official name for Vitamin U. A sulfur-containing compound that plants make from the amino acid methionine, found in cruciferous vegetables and most of all in raw cabbage.
You'd need about a liter of raw cabbage juice to get the 500 mg that's in one capsule. It also has to be made fresh, and it tastes like raw cabbage juice.
Take 1 capsule once or twice daily with food.
Yes. The capsule shell is plant-based (hypromellose), and nothing in the formula comes from animals.
Because of what's in them, and it's a good sign. S-methylmethionine is a natural sulfur compound, and sulfur has a smell. If your bottle smells a little like cabbage, you have the real thing. Keep it in a cool, dry place, and the smell settles down once the bottle has been open for a while.
Yes. Pick a delivery plan above the Add to cart button and you save 10% on every order, not only the first, and you never run out. One capsule a day: choose every 2 months. Two capsules a day: choose every month.
Click the account icon at the top of any page, enter your email, and we send you a 6-digit code to sign in. Then open Subscriptions and click Manage. No minimum, no fee, and no need to email us.
30 days. Send us a message and we'll refund you in full. You don't need to send the bottle back.
References

1. Watanabe et al., on gastric mucin in animal and cell studies. Reviewed in Ananian et al., Pharmaceuticals 19(5):743, 2026.

2. Determination of Vitamin U in Food Plants, Food Science and Technology Research 9(4):316, 2003.