Peptide & Experimental
SAM-e (S-adenosylmethionine)
The body’s own methyl group donor; prescription-only active substance in Germany, unauthorized novel food as a food supplement · SAMe, S-adenosyl-L-methionine, AdoMet, ademetionine (INN), Samyr, Donamet (Italy), disulfate tosylate, butanedisulfonate
SAM-e is the body’s most important methyl group donor and an approved medicine in Italy for depression and bile congestion in the liver. In a meta-analysis of 23 randomized studies on depression, it performed similarly to classic antidepressants in direct comparison. How strongly it beats placebo, however, is disputed, and in Germany it is prescription-only.
In short
SAM-e, written out S-adenosylmethionine, is made by every body cell from the amino acid methionine, most of all by the liver. It supplies the methyl groups for practically all methylations and is a precursor of glutathione. The latest meta-analysis of 23 studies found a medium advantage over placebo for depression and no difference from antidepressants; earlier reviews and the largest modern study saw no clear advantage over placebo. In osteoarthritis, older studies found it about as effective as painkillers from the NSAID group; in liver cirrhosis, the benefit is not established. In Germany, ademetionine is prescription-only, and the usual capsule form has been considered an unauthorized novel food since 2026.
What it is
SAM-e is formed in every body cell from the amino acid methionine by the enzyme methionine adenosyltransferase, most of all in the liver. The molecule is the central methyl group donor of metabolism and supplies the methyl groups for all known biological methylations. It is also involved in building glutathione, the cell’s most important protective substance against oxidative stress.
As a medicinal substance, SAM-e is called ademetionine. In Italy it is approved as a prescription medicine under the names Samyr and Donamet, for depressive syndromes in adults and for bile congestion in the liver, including in pregnancy. In the US it is sold as a food supplement. Because the molecule is unstable, it is usually marketed as a salt, for example as disulfate tosylate or as butanedisulfonate.
How it is supposed to work
For the liver, the logic is clearest. The liver makes the most SAM-e, and in chronic liver disease the producing enzyme and SAM-e levels are reduced. Mice lacking the liver enzyme develop fatty liver inflammation, which regresses with SAM-e. The flip side is interesting: permanently too much SAM-e in the liver is also harmful, as children with a congenital breakdown defect show. So more is not automatically better here.
How SAM-e works against depression has not been clarified. There is no mode of action demonstrated in humans. The Italian summary of product characteristics states that vitamin B12 and folic acid deficiency can reduce the effect, which fits the role of SAM-e in the methylation cycle without explaining the mechanism.
A long research history
SAM-e is not a new trend substance but has been the subject of clinical research for decades. An evidence report by the US agency AHRQ from 2003 already analyzed 47 studies on depression, 28 of them in a meta-analysis. Compared with placebo, SAM-e improved the Hamilton Depression Scale there by about 6 points; compared with antidepressants, there was no significant difference. On osteoarthritis the authors found 14 studies, and in intrahepatic cholestasis of pregnancy an effect of almost a whole standard deviation. The report has since been marked as historical. The newer meta-analyses paint a similar picture but are considerably more cautious in the comparison with placebo.
What is well supported
Depression is the best-studied field. The most recent systematic review with 23 randomized studies and 2,183 participants found a standardized difference of −0.58 for SAM-e alone versus placebo, that is, a medium effect, with moderate certainty of evidence. In direct comparison with antidepressants there was no difference in 7 studies, and dropout rates were not higher. As an add-on to an SSRI in people whom the antidepressant alone did not help, response rose in one study from 17.6 to 36.1 percent and remission from 11.7 to 25.8 percent. In osteoarthritis, a meta-analysis of 11 studies found an effect similar to classic painkillers from the NSAID group, with fewer side effects. Against the modern painkiller celecoxib, SAM-e acted more slowly in a crossover study but was on a par from the second month. In the liver, it lowered liver values in bile congestion within 2 weeks in placebo-controlled studies; it is approved for this in Italy.
What the studies show
SAM-e as an add-on to an SSRI
73 people with depression in whom an SSRI was not working sufficiently additionally received SAM-e, target dose 800 mg twice daily, or placebo for 6 weeks. Response 36.1 versus 17.6 percent, remission 25.8 versus 11.7 percent. 5.1 percent on SAM-e and 8.8 percent on placebo dropped out because of side effects.
Three-way contest with escitalopram
189 outpatients, 12 weeks, SAM-e 1,600 to 3,200 mg per day, escitalopram or placebo. All three groups improved by about 5 to 6 points; response 36, 34 and 30 percent. Neither SAM-e nor the established antidepressant beat placebo; the study shows above all a high placebo effect.
Two years in liver cirrhosis
123 patients with alcoholic liver cirrhosis received 1,200 mg SAM-e daily or placebo for 2 years. Death or liver transplantation occurred in 16 versus 30 percent, which was not significant. Excluding the patients in the most severe stage, the difference of 12 versus 29 percent was significant. No serious side effects occurred during the 2 years.
Where the data stop
Whether SAM-e really beats placebo in depression is answered differently by the reviews. The 2016 Cochrane review with 8 studies and 934 adults found no clear difference from placebo, with very low quality of data; a further 2024 meta-analysis with 14 studies did not either. The daily doses used ranged from 200 to 3,200 mg, the studies lasted at most 12 weeks, and some older ones used infusion instead of capsules. In osteoarthritis, the 2009 Cochrane review arrives at only 0.4 cm difference in pain on a 10 cm scale, with poor study quality, and advises against routine use. In liver cirrhosis, the most important study missed its main goal, and the US health agency NCCIH does not consider the benefit in liver disease proven. For longevity, methylation optimization or well-being in healthy people there are no studies.
Status, approval and legal
In Germany, ademetionine is listed in Annex 1 of the German Ordinance on Prescription-Only Medicines (AMVV), which means medicines containing its salts are also prescription-only. The stabilized form common in capsules, S-adenosyl-L-methionine disulfate tosylate, was classified as a novel food by the EU Commission on May 20, 2026, because no significant consumption as a food before May 15, 1997 has been documented; there is no authorization. On July 2, 2026, Italy reported such a product in the European rapid alert system as an unauthorized novel food. SAM-e is nevertheless offered as a food supplement in Germany; under this situation it is not marketable as a food. We therefore list it among the experimental substances. In Italy it is a prescription medicine, in the US a food supplement. The World Anti-Doping Agency’s 2026 Prohibited List does not mention SAM-e.
Safety
The most common side effects affect the gastrointestinal tract. In the large depression study, 19 percent had stomach complaints and 20 percent diarrhea; at 3,200 mg per day, 31.3 percent complained of abdominal discomfort. More important is the psyche: in bipolar disorder, SAM-e can trigger hypomania or mania; the Cochrane review counted 2 such cases among 441 treated, and the Italian summary of product characteristics explicitly warns about this. Caution is needed with SSRIs, tricyclic antidepressants, tryptophan or St. John’s wort; a serotonin syndrome has been described with clomipramine. The effect of levodopa in Parkinson’s disease can be weakened. It should not be taken by anyone with a congenital defect of methionine metabolism or homocystinuria. Safety in pregnancy has not been established, and there are theoretical concerns in immunodeficiency. Anyone who takes antidepressants or has a mental illness should clarify SAM-e with a doctor beforehand.
BK-Score Supported, with caveats
| Human evidence | 6 | |
|---|---|---|
| Mechanism | 6 | |
| Safety data | 7 | |
| Hype gap | 6 | |
| Track record of use | 7 |
Evidence 6, because there are many randomized studies, but they are mostly small and short and contradict each other: SMD −0.58 versus placebo in the meta-analysis with 23 RCTs and 2,183 participants (Limveeraprajak et al. 2024), but no clear difference in the Cochrane review with 8 studies and 934 adults (Galizia et al. 2016) and no advantage over placebo in the largest modern study with 189 patients (Mischoulon et al. 2014); in osteoarthritis only 0.4 cm on a 10 cm scale with poor study quality (Rutjes et al. 2009), in alcoholic cirrhosis primary endpoint missed (Mato et al. 1999, 123 patients, p = 0.077). Mechanism 6, because the role as methyl group donor and glutathione precursor is biochemically established and SAM-e deficiency in chronic liver disease has been measured in humans (Lu & Mato 2012), but the mode of action against depression remains open. Safety 7, because controlled data over 2 years without serious side effects are available and it is approved as a medicine with a summary of product characteristics in Italy, but publicly accessible long-term pharmacovigilance is missing; known risks are mania in bipolar disorder and serotonergic interactions. Hype 6, because marketing as a natural antidepressant and joint remedy is mostly based on real studies, but the uncertainty in the comparison with placebo is usually concealed. Use 7, because SAM-e is used in a regulated way as a prescription medicine in Italy and has been sold widely as a food supplement in the US for years. Direction mixed: positive meta-analysis and SSRI add-on study, neutral results in the Cochrane review, in the largest depression study and in cirrhosis.
The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)
Frequently asked questions about SAM-e (S-adenosylmethionine)
Does SAM-e work against depression?
The latest meta-analysis of 23 studies found a medium advantage over placebo and no difference from antidepressants. The 2016 Cochrane review and the largest modern study, by contrast, saw no clear advantage over placebo. SAM-e is therefore a serious candidate, but not as well established as approved antidepressants.
Can SAM-e be combined with antidepressants?
In one study, SAM-e helped as an add-on to an SSRI when the SSRI alone was not enough. However, there is a risk of serotonin syndrome; a case with clomipramine has been described. The combination therefore belongs in the hands of a physician.
Does SAM-e help with osteoarthritis?
Older studies found an effect similar to classic painkillers with fewer side effects. The Cochrane review sees only a small effect versus placebo with weak study quality and advises against routine use.
Is SAM-e allowed in Germany?
Ademetionine is prescription-only in Germany. The usual capsule form has been considered an unauthorized novel food throughout the EU since May 2026. As a food supplement, SAM-e is therefore not marketable, even though it is offered.
What side effects does SAM-e have?
The most common are stomach complaints, diarrhea and nausea, especially at high doses. In bipolar disorder it can trigger mania. The effect of levodopa can be reduced.
What does SAM-e do for the liver?
In Italy it is approved for bile congestion in the liver and lowered liver values quickly in studies there. In alcoholic liver cirrhosis, the most important two-year study missed its main goal; only in less severely ill patients was the difference significant.
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Sources
- Limveeraprajak et al., Prog Neuropsychopharmacol Biol Psychiatry 2024 – meta-analysis on depression, 23 RCTs
- Galizia et al., Cochrane Database Syst Rev 2016 – SAMe in depression
- Papakostas et al., Am J Psychiatry 2010 – SAMe as an add-on to SSRIs
- Mischoulon et al., J Clin Psychiatry 2014 – SAMe vs. escitalopram vs. placebo
- Rutjes et al., Cochrane Database Syst Rev 2009 – SAMe in osteoarthritis
- Soeken et al., J Fam Pract 2002 – meta-analysis on osteoarthritis
- Mato et al., J Hepatol 1999 – alcoholic liver cirrhosis, 2 years
- Lu and Mato, Physiol Rev 2012 – SAMe in liver health and disease
- NCCIH – S-Adenosyl-L-Methionine (SAMe): In Depth
- EU Commission – novel food status of S-adenosyl-L-methionine disulfate tosylate
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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-09-27.