Hard training generates a flood of free radicals in your muscles — the kind of oxidative stress that accelerates fatigue, slows recovery, and chips away at your immune system over time. Your body's primary defense against all of that is glutathione, and most endurance athletes are burning through it faster than they can replenish it. Pure Encapsulations NAC gives your body the raw material it needs to rebuild glutathione levels and fight back against training-induced oxidative damage. N-Acetyl-L-Cysteine is the most bioavailable form of cysteine — the amino acid that's the rate-limiting factor in glutathione production. Your Body's Antioxidant Fuel – NAC is a direct precursor to glutathione, your body's most powerful internal antioxidant. When training depletes your glutathione reserves, NAC helps restore them so your cells can neutralize the free radicals that contribute to fatigue and delayed recovery. Supports Respiratory and Lung Health – NAC has a natural affinity for lung tissue, where it supports healthy mucus clearance and protects the airway cells that take a beating during high-output breathing in cold, dry, or polluted conditions. A randomized trial with 262 participants showed NAC supplementation for six months supported upper respiratory and immune health. Immune System Backup for Hard Training – Your immune cells (specifically lymphocytes) depend on glutathione to function properly. Heavy training blocks and race buildups suppress immune function — NAC helps keep your defenses up when your training load is highest. NAC works by donating a cysteine molecule to your cells, which they use to synthesize glutathione — the antioxidant that protects cell membranes, supports detoxification in your liver, and keeps your immune system running. Research in endurance athletes has shown that NAC supplementation enhances muscle cysteine and glutathione availability and can help delay fatigue during prolonged exercise. How to Use NAC Daily Use: Take 1 capsule, 1-3 times daily, between meals for optimal absorption. Training Blocks: During high-volume training phases or race buildups, take the full 3-capsule daily dose (1,800 mg) split across the day to maximize glutathione support. Endurance athletes, particularly those in high-volume training cycles, are among the most susceptible to glutathione depletion and exercise-induced oxidative stress. Pure Encapsulations delivers pharmaceutical-grade, free-form NAC in a clean vegetarian capsule with zero unnecessary additives — the same quality standard that's made them the #1 most recommended professional supplement brand.
