2 doctors weighed in:
Are there any side effects of l-lysine?
2 doctors weighed in

Dr. Rick Kirschner
General Practice
1 doctor agrees
In brief: High doses, maybe
Deficiency symptoms might include stomach cramps, diarrhea, hair loss weight loss, poor concentration, reproductive problems, kidney stones.
It can interact with a number of antibiotics to lethal effect. It could cause severe allergic reactions, (swelling of lips and tongue, or throat closure, difficulty breathing) old people need it more than young. Athletes use it.

In brief: High doses, maybe
Deficiency symptoms might include stomach cramps, diarrhea, hair loss weight loss, poor concentration, reproductive problems, kidney stones.
It can interact with a number of antibiotics to lethal effect. It could cause severe allergic reactions, (swelling of lips and tongue, or throat closure, difficulty breathing) old people need it more than young. Athletes use it.
Dr. Rick Kirschner
Dr. Rick Kirschner
Thank
Get help from a real doctor now
Dr. Vicken Poochikian
Board Certified,
38 years in practice
2M people helped
Continue
107,000 doctors available
Read more answers from doctors