Frequently asked questions
Everything you want to know about Vitamin U
About Vitamin U
The basics
Vitamin U is the common name for S-methylmethionine (SMM), a naturally occurring compound found in cabbage and other cruciferous vegetables. It was named "Vitamin U" by researcher Garnett Cheney at Stanford in the 1950s. The U stands for ulcers. It isn't technically a vitamin by modern definition, but the name stuck.
Not in the strict scientific sense. Classical vitamins are essential nutrients the body can't produce and must get from food. S-methylmethionine doesn't fit that definition. It was called Vitamin U by researchers in the 1950s while studying it. The name stuck, even though the science has moved on.
It's found naturally in cabbage, kale, Brussels sprouts, and other cruciferous vegetables, and in smaller amounts in celery, asparagus, and spinach. Raw cabbage juice is the most concentrated food source, which is why cabbage juice has been used historically for stomach problems. Why a supplement beats cabbage juice →
Research suggests S-methylmethionine supports the stomach lining in two ways: it may help the stomach produce more protective mucus (the gel-like layer that coats the stomach wall), and it may help repair mucosal cells that have been damaged. It also acts as a methyl donor and antioxidant. See our Global Vitamin U Research Database for the full evidence.
S-methylmethionine can't be patented. It's a naturally occurring compound, which means there's no financial incentive to fund the expensive clinical trials required for FDA drug approval in the United States. Japan and Ukraine incorporated it into clinical practice based on decades of research. In the US, it remains available as a dietary supplement.
Dosage and timing
How to take it
One to two VitaminYOU capsules per day (500 to 1,000 mg of S-methylmethionine). Most people start with one capsule daily and increase to two if needed. Human trials have used doses from 300 mg/day up to 2,000 mg/day. VitaminYOU provides 500 mg per capsule.
With food is generally recommended, both for tolerability and because the stomach is actively working to digest a meal, which makes it a good time to support the mucosal lining. Morning or evening both work; consistency matters more than timing.
Yes. Two capsules daily (1,000 mg) is within the range that appears in research and in common use. If you're just starting, beginning with one capsule for the first week or two and increasing is a reasonable approach.
S-methylmethionine is generally considered well-tolerated alongside other common supplements. No significant interactions with common supplements have been reported in the literature. If you're taking prescription medications, check with your doctor.
Safety
Is it safe?
No serious adverse effects have been reported in any published human study at supplementation doses. The safety profile across 70+ years of research and prescription use in Japan and Ukraine is favorable. If you have a medical condition, are pregnant, or take prescription medications, speak with your doctor before starting any new supplement.
No significant side effects have been reported in the published research.
Many people take VitaminYOU alongside PPIs or H2 blockers. Vitamin U works through a different mechanism (supporting the mucosal lining) rather than reducing acid, so it is often used as a complement to acid-reducing therapy. That said, if you're on prescription medications, always confirm with your prescribing physician before adding a supplement.
There is insufficient safety data for use during pregnancy or breastfeeding. We recommend avoiding it during pregnancy and breastfeeding and consulting your OB or midwife if you're considering it.
What to expect
Results timeline
Some people notice improvement within days. Others notice it over a few weeks of consistent use. The most recent long-duration human trial (Drozdov 2023) tracked patients over 6 months and found significant symptom improvement, which suggests that for some, the benefits build gradually. Give it at least 3 to 4 weeks before evaluating. If you're in an active flare, relief may come faster.
Try increasing to two capsules daily if you started at one. Give it a full 30 days. If you still don't notice a difference, contact us. Our 30-day guarantee means you can get a full refund, no questions asked. We want to hear from you either way.
The product
What's inside
S-Methylmethionine (Vitamin U), 500 mg per capsule. Three inactive ingredients: hypromellose (the capsule shell), magnesium stearate, and silicon dioxide. That's it.
Yes. The capsule shell is made from hypromellose, a plant-derived material. All other ingredients are non-animal derived.
Yes. VitaminYOU is third-party tested for purity and potency.
VitaminYOU is manufactured in the United States in a GMP-certified facility.
Yes. Vitamin U has a natural sulfur note, a bit like cabbage or cooked vegetables. That's the compound itself, not a sign anything is wrong. It's the same reason raw cabbage juice, the traditional source of Vitamin U, smells the way it does. Exposure to heat and air speeds up that natural breakdown and makes the smell stronger, so keep the bottle sealed in a cool, dry place.
VitaminYOU is a dietary supplement, not a drug. Under US law, dietary supplements are not individually approved by the FDA. Our facility is FDA-registered and GMP-certified. The product label complies with FDA dietary supplement regulations.*
*This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
Shipping and returns
Orders and delivery
We ship to all 50 US states. We don't currently ship internationally.
Orders are processed within 1 to 2 business days. Standard delivery typically takes 3 to 7 business days after shipment. See our Shipping Policy for full details.
30-day satisfaction guarantee. If you're not happy for any reason, email us at hello@vitaminyou.shop within 30 days of delivery and we'll issue a full refund. You don't need to return the bottle. See our Returns and Refunds Policy.