Methionine
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
Methionine: From Amino Acid Nutrition to Acne
One-Sentence Summary
Methionine is an essential sulphur-containing amino acid. In South Africa it is registered as a component of amino acid and parenteral nutrition products. The TxGNN model predicts it may be useful for acne, but there are 0 clinical trials and only 4 indirect publications (no randomised trials), and none of them tests methionine as a treatment.
Quick Overview
| Item | Content |
|---|---|
| Predicted New Indication | Acne |
| TxGNN Prediction Score | 99.9996% |
| Evidence Level | L4 |
| South Africa Market Status | Marketed |
| Number of SAHPRA Registrations | 11 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Methionine is a building block for proteins and the precursor of S-adenosylmethionine (SAM), homocysteine and, via transsulfuration, cysteine and glutathione. The registered products are nutritional (amino acid infusions and dialysis solutions), not treatments for a skin disease.
The link to acne is weak and indirect. The only relevant paper is a 2001 cohort study showing that plasma homocysteine rose in patients taking isotretinoin for cystic acne. Homocysteine is a methionine metabolite, so this links acne therapy to methionine metabolism. It does not show that methionine helps acne. Supplementing methionine could raise homocysteine, so the direction of any effect is unclear and may be harmful. The other three papers concern an MTHFR-related neonatal syndrome, Sweet’s syndrome and neutrophil chemotaxis, and none addresses methionine for acne. The TxGNN score is a model output only.
Clinical Trial Evidence
Currently no related clinical trials registered (ClinicalTrials.gov, ICTRP, SANCTR or PACTR were not found in the evidence provided).
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 11277950 | 2001 | Cohort | Int J Dermatol | Plasma homocysteine was elevated in patients on isotretinoin for cystic acne. This is an indirect link to methionine metabolism. |
| 39357918 | 2024 | Case report | BMJ Case Reports | A novel MTHFR mutation in a neonate with encephalopathy, hair loss and marfanoid features. Neonatal acne was one of several skin findings. |
| 3859500 | 1985 | Lab study | J Am Acad Dermatol | Increased plasma chemoattractant in a patient with Sweet’s syndrome and cystonodular acne. Not related to methionine. |
| 3161955 | 1985 | Lab study | J Invest Dermatol | Transient loss of C5a-specific neutrophil function in inflammatory skin disorders, including acne conglobata. Not related to methionine. |
South Africa Market Information
Approved-indication text and manufacturer are not recorded in the registration data. EML status is not available. Of the 11 registrations, 5 are shown:
| Registration Number | Product Name | Dosage Form |
|---|---|---|
| Reg. No. 37/34/0243 | Nutrineal PD4 with 1.1% amino acids 2.5L | Infusion |
| Reg. No. 33/10.2.1/0271 | Adco-ipratropium (ni201) | Vial |
| Reg. No. 38/34/0172 | Extraneal 2L single bag | Infusion |
| Reg. No. 37/25.2/0503 | Oliclinomel N6 900E 2000ml | Infusion |
| Reg. No. 41/25/0757 | Nutriflex Lipid Peri | Infusion |
Note: Adco-ipratropium is not an obvious methionine-containing product. Please verify this registration mapping against the SAHPRA record.
Safety Considerations
Please refer to the SAHPRA-approved Professional Information (PI) for safety information. Report adverse drug reactions to SAHPRA.
No drug-interaction records were found in the data provided. Independent of the PI, the acne evidence suggests one theoretical concern. Methionine can raise homocysteine, which is itself associated with vascular and ocular disease.
Conclusion and Next Steps
Decision: Hold
Rationale: Acne is supported only by an indirect observational paper, with no clinical trials and a mechanism that may point the wrong way. The other top-ranked predictions are mostly cataract and diabetic eye conditions. They also have no trials, and their literature is preclinical or mechanistic (L4–L5), so they do not change this decision.
To proceed, the following is needed:
- The SAHPRA package inserts for the relevant products, to complete safety screening
- Mechanism of action data (for example from DrugBank)
- A structured review of whether methionine or homocysteine modulation has any plausible effect on acne, including the risk of raised homocysteine
- Any human clinical data on methionine or SAM-cycle modulation in acne. If none exists, the candidate should stay at Hold.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.