Methylmethionine sulfonium
Evidence: MixedUseful mainly for no well-established clinical use; historical interest in gastric mucosal protection.
Quick decision guide
May help most
no well-established clinical use; historical interest in gastric mucosal protection
Common dosing range
No established dose; older products used roughly tens of milligrams to a few hundred mg/day
When to expect effects
Unclear
Watch out for
Human evidence is old and very limited; not a substitute for treatment of ulcers or reflux
What is it
Methylmethionine sulfonium (S-methylmethionine), historically nicknamed 'vitamin U,' is a methylated amino-acid derivative found in cabbage and other vegetables. It was studied decades ago for protecting the stomach lining and is sometimes marketed for digestive complaints.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Evidence | Effect | Best fit | Time |
|---|---|---|---|---|
| gastric mucosal protection | Mixed Evidence | Unclear | not established | Unclear |
Evidence for 1 use
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
gastric mucosal protection
Mechanism onlyEarly and largely preclinical work suggested S-methylmethionine may support the gastric mucosa, the basis for its old 'vitamin U' anti-ulcer reputation. There are no robust modern randomized trials demonstrating clinical benefit in humans.
Bottom line: Any gastric-protective effect is supported only by old and mechanistic data, not by modern clinical evidence.
How to take it
- Typical dose
- No standardized dose established
- Timing
- Historically taken with meals
- With food
- With food
- How long to try
- Not established
What to track
- Upper-abdominal symptoms
- Heartburn frequency
Safety
Common side effects
Not well characterized; generally regarded as low-risk at dietary amounts
Who should avoid it
- People using it in place of evaluated treatment for ulcers or reflux
Pregnancy & breastfeeding
No adequate safety data; avoid supplemental use in pregnancy and breastfeeding.
Choosing a product
Look for
- Clear identification as S-methylmethionine
- Stated amount per serving
Be skeptical of
- 'Vitamin U cures ulcers'
- 'Heals the gut lining'
References by claim
gastric mucosal protection
- Maxis et al., 1965 — PubMed (1965) link
Track Methylmethionine sulfonium with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.