Thorne Lysine

Endurance athletes break down connective tissue constantly — tendons, ligaments, cartilage, and bone all absorb the mechanical load of thousands of repetitive footstrikes, pedal strokes, and swim cycles every week. The body rebuilds that tissue through collagen synthesis, and collagen synthesis doesn't happen without lysine.

It's one of nine essential amino acids your body can't produce on its own, and it's a direct structural requirement for building the connective tissue that keeps joints healthy and injuries at bay. Most athletes focus on protein intake and miss this piece entirely.

Thorne Lysine delivers 500mg of pure L-Lysine Monohydrochloride per capsule — the most bioavailable form available, with nothing added.

The Collagen Building Block Athletes Need – Collagen is the primary structural protein in your tendons, ligaments, cartilage, skin, and bone. Lysine is one of the key amino acids required to synthesize it. Without adequate lysine, your body can't produce or repair collagen effectively, and for high-volume athletes putting constant stress on connective tissue, that gap shows up as slower recovery from soft-tissue injuries, persistent joint soreness, and reduced structural resilience over time.

Supports Bone Density Through Calcium Utilization – Lysine plays a direct role in how your body absorbs and uses calcium — the mineral that determines bone density. It helps facilitate calcium transport into bone tissue and reduces urinary calcium loss, making it a meaningful complement to any bone health strategy for athletes who train at high volume on hard surfaces.

Immune Defense When Training Load Is High – Intense training suppresses immune function temporarily, and lysine supports the body's natural defenses during those vulnerable windows. Lysine also helps maintain a healthy balance between itself and arginine — an amino acid that can be exploited by certain viruses when lysine levels run low. For athletes who get cold sores or feel run down during peak training blocks, this is worth noting.

Lysine is primarily found in meat, poultry, fish, dairy, and legumes. Athletes eating high-carbohydrate training diets — or plant-based athletes who rely heavily on grains (which are naturally low in lysine) — are most likely to fall short. Thorne's formula uses the purest form of this amino acid with no unnecessary additives or fillers.

How to Use Thorne Lysine

Daily Dose: Take 1 capsule two to three times daily with food, or as recommended by your healthcare practitioner. Spreading doses across meals supports consistent amino acid availability throughout the day.

For Connective Tissue Support: Research on collagen synthesis suggests that amino acid availability around training — particularly in the 30–60 minutes before loading connective tissue — may improve tissue adaptation. Consider taking one dose before key training sessions.

Pro Tip: Lysine works best when paired with adequate vitamin C, which is also required for collagen synthesis. If you're using lysine specifically for connective tissue support, ensure your vitamin C intake is solid.