Last verified: 17 days ago
L-Lysine
Also known as: lysine, L-Lys, 2,6-diaminohexanoic acid
Evidence under review. — Not yet rated
Essential amino acid found in food and supplements. Limited clinical evidence for most popular health claims.
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What it does
L-Lysine is an essential amino acid your body cannot make on its own — you must get it from food or supplements. It plays a role in protein synthesis, collagen formation, and calcium absorption....
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose
What the Science Says
L-Lysine is an essential amino acid your body cannot make on its own — you must get it from food or supplements. It plays a role in protein synthesis, collagen formation, and calcium absorption. One provided study included L-Lysine as part of a multi-ingredient supplement for spinal disc health, but no benefit over placebo was found in that combination formula.
What It Doesn't Do
No evidence from these studies that it treats herpes outbreaks on its own. Not shown to build muscle or improve athletic performance here. The multi-ingredient spine supplement it was part of showed no significant benefit. Don't expect it to work as a standalone treatment for any condition based on this data.
Evidence-Based Benefits
As part of a supplement blend, L-Lysine did not significantly improve lumbar disc pain or function vs. placebo.
Weak EvidenceEffective at: No established dose
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Unknown based on provided studies — no pharmacokinetic data in the provided papers.
Red Flags to Watch For
- Most provided research involves poly-L-lysine (a polymer used in lab/medical devices), not the dietary supplement form — these are very different things.
- The one clinical trial including L-Lysine as a supplement ingredient showed no significant benefit over placebo.
- L-Lysine appeared as a metabolic biomarker in a hypertension study — this does not mean supplementing it treats hypertension.
- Widely marketed for cold sore prevention, but none of the provided studies support this claim.
Products Containing L-Lysine
See how L-Lysine is used in these analyzed products:
Elm & Rye Vegan Protein Blend
Supplement
Thorne Amino Complex Berry Powder NSF
Supplement
Double Wood Supplements Essential Amino Acids
Supplement
Optimum Nutrition 100% Gold Standard Whey
Supplement
Swolverine INTRA
Supplement
Hormone Harmony PLUS+
Supplement
Everyday Dose
Supplement
Frequently Asked Questions
What does L-Lysine do?
Essential amino acid found in food and supplements. Limited clinical evidence for most popular health claims.
What is the effective dose of L-Lysine?
No established dose
Is L-Lysine safe?
Most provided research involves poly-L-lysine (a polymer used in lab/medical devices), not the dietary supplement form — these are very different things.
What doesn't L-Lysine do?
No evidence from these studies that it treats herpes outbreaks on its own.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25