Alpha-lipoic acid
Alpha-lipoic acid is a small sulphur-containing fatty acid that the body makes in small amounts and uses as a helper for energy-producing enzymes in mitochondria. Inside cells it is reduced to dihydrolipoic acid, its antioxidant form.
Also called ALA, lipoic acid, thioctic acid.
Its link to glutathione is indirect. In several cell types grown in the lab, none of them cartilage, lipoic acid substantially raised reduced glutathione, but only after the cells converted it to dihydrolipoic acid, which turned cystine outside the cell into cysteine that the cells could readily take up (Han 1997). It mainly restored cells that were short of glutathione rather than pushing healthy cells above normal levels (Han 1997).
In cartilage research, alpha-lipoic acid lessened cartilage damage in a rat model of osteoarthritis, raised collagen type II and aggrecan gene activity and lowered markers of oxidative damage (Wang 2016). Its reduced form protected glutathione and GPX4 in mouse cartilage cells and slowed cartilage damage in mice (Chen 2026).
Sources
- Han D, Handelman G, Marcocci L et al. Lipoic acid increases de novo synthesis of cellular glutathione by improving cystine utilization. Biofactors 1997.
- Wang J, Sun H, Fu Z et al. Chondroprotective effects of alpha-lipoic acid in a rat model of osteoarthritis. Free Radic Res 2016.
- Chen Y, Fang J, Zhou Z et al. Dihydrolipoic acid suppresses ferroptosis in chondrocytes to ameliorate the progression of osteoarthritis by modulating the FOXO1/TXNIP signaling pathway. Free Radic Biol Med 2026.
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