Life Extension L-Lysine, 620 mg, Essential Amino Acid for Healthy nitrogen Balance, Calcium Metabolism, Stress Response & More, Gluten-Free, Non-GMO, Vegetarian, 100 Capsules

Customers find the L-Lysine supplement effective for healing canker sores, shingles, and boosting the immune system, while also appreciating its good value and ease of swallowing. The product receives positive feedback for its quality, with one customer noting it's a good replacement for tablets. The pill size receives mixed reactions, with some finding it good-sized while others consider the capsules too large. Customers report mixed experiences with side effects, with some experiencing stomach pain and bloating.