Oral hyaluronan relieves knee pain: a review

Oe M, Tashiro T, Yoshida H, et al. · Nutrition Journal

All 13 reviewed trials reported symptom relief; proposed mechanisms include receptor-mediated (TLR4/CD44) intestinal signalling and increased endogenous HA synthesis, since intact high-molecular-weight HA is barely absorbed.

Population

Review of 13 human trials of oral hyaluronan for knee pain plus mechanism studies

Intervention

Oral hyaluronic acid 80-240 mg/day, 2 weeks to 12 months

Comparator

Mostly placebo

Limitations

Authors are affiliated with Kewpie Corporation, an HA manufacturer; the uniformly positive trial set (largely small Japanese studies) suggests publication and sponsorship bias.