L-lysine is a necessary amino acid to maintain healthy tissues, especially collagen fibers. L-lysine provides the firm structure necessary for both skin and joint elasticity and integrity. Although research on lysine and growth hormone secretion is limited to small studies, no strong evidence exists to support athletic enhancements due to its ingestion. However, lysine is essential in repairing tissues, and therefore strongly aids recovery. Safety concerns are low; however, clinicians must exercise caution with patients who have impaired kidney function due to the increased amino acid load on the kidneys.
Founder & Medical Director at New York Cosmetic Skin & Laser Surgery Center
Answered 4 months ago
As a board certified dermatologist and dermatologic surgeon, I look at L-lysine first as a collagen amino acid. Lysine residues are hydroxylated and then create cross links that stabilize type I collagen fibrils in skin, bone, and cartilage. When patients are protein deficient, I see slower wound healing, weaker scars, and more crepey skin. Good lysine intake, with vitamin C and enough total protein, supports a stronger dermal matrix and healthier connective tissue. For HGH, my view is cautious. Older studies show large oral doses of L-lysine plus L-arginine can briefly raise GH at rest, but not during exercise, and athletic benefits are inconsistent. In my practice I do not use lysine or arginine as HGH boosters. I rely on sleep, resistance training, and adequate calories, then add amino acids only if diet is clearly lacking. Recent 2025 data on lysine biology support its role in collagen structure: https://pmc.ncbi.nlm.nih.gov/articles/PMC12469518/