N-acetyl-cysteine, or NAC, is an antioxidant compound. Given by mouth to rats, it held back MMP13 and the loss of type II collagen in a joint damage model.
Also called NAC, N-acetyl cysteine, acetylcysteine.
Kaneko and colleagues looked at oxidative stress as a link between mechanical load and cartilage damage (Kaneko 2019). In rats, mechanical stress led to a build-up of reactive oxygen species in cartilage cells and to cell death. In cultured cartilage cells, mechanical stress raised reactive oxygen species and inflammatory messengers, and NAC blocked both (Kaneko 2019).
Given by mouth in a rat model of joint damage, NAC significantly held back the joint changes. MMP13 expression, the fall in type II collagen and cartilage cell death were all reduced (Kaneko 2019). The untreated, sham-operated side of each rat also developed changes, probably from altered weight-bearing, and NAC reduced those too.
This is one rat study. The abstract doesn't give the dose, and it doesn't show what NAC does in human joints.
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