Avocado-soybean unsaponifiables
Three meta-analyses report small reductions in osteoarthritis pain and better function than placebo with 300 mg a day, mostly in knee rather than hip osteoarthritis. All four trials in one review were supported by the manufacturer. Mean joint space loss did not differ over 3 years. Adverse events matched placebo.
Add to Bio HackChecked 2026-11-09
- Status
- Sold as a dietary supplement in the US. Not FDA-approved as a drug for any condition.
- Also called
- ASU, avocado soybean unsaponifiables, avocado/soybean unsaponifiables, avocado soya unsaponifiables, Piascledine, Piasclidine, ASU-E
- Taken for
- osteoarthritis, knee osteoarthritis, hip osteoarthritis, joint pain, cartilage
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help1
Reported risks0
No risks sourced yet.
What people take it for, and what was found
Shown to help1
Osteoarthritis pain and function
Shown to lower osteoarthritis pain by about 8.5 points on a 100-point scale in adults with hip or knee osteoarthritis. All trials in one review were maker-supported.
The numbers and sources
- Effect
- In a Cochrane review, 300 mg a day for 3 to 12 months lowered pain by 8.5 points on a 100-point scale (95% CI 1 to 16) from 40.5 on placebo, and improved function (SMD -0.42, 95% CI -0.73 to -0.11) (4 trials, 651 participants, moderate quality) [1]. A meta-analysis of 4 trials (664 patients) found less pain (effect size 0.39, 95% CI 0.01 to 0.76, I² 83.5%) and lower Lequesne index scores (0.45), with a number needed to treat of 6 [2]. A third meta-analysis found pain 9.64 mm lower on a 100 mm scale (95% CI -17.43 to -1.84, I² 92%). In knee osteoarthritis, pain was 17.36 mm lower and the Lequesne index 2.33 points lower, with no significant change in hip osteoarthritis [3].
- Population
- Adults with hip or knee osteoarthritis, 58.6% knee and 41.4% hip in one review [2].
- Sources
- [1], [2], [3]
- Caveats
- All four trials in one review were supported by the manufacturer [2]. Heterogeneity was high [2][3]. The Cochrane authors describe the symptom gain as small and clinically questionable, and less convincing over longer terms and against active controls [1].
Not shown to help1
Joint structure
Not shown to slow joint space loss in hip or knee osteoarthritis. In one hip trial, fewer people lost 0.5 mm or more, a secondary measure.
The numbers and sources
- Effect
- In 2 studies (453 participants), loss of joint space width did not differ between 300 mg a day (-0.53 mm) and placebo (-0.65 mm), a difference of -0.12 mm (95% CI -0.43 to 0.19) [1]. In a 3-year trial of 399 people with hip osteoarthritis, mean joint space loss did not differ (-0.638 mm against -0.672 mm, p 0.72), while fewer people lost 0.5 mm or more (40% against 50%, p 0.040). Symptoms did not differ [4].
- Population
- Adults with hip or knee osteoarthritis [1], and 399 adults with symptomatic hip osteoarthritis, 345 analyzed [4].
- Sources
- [1], [4]
- Caveats
- The share of progressors was a secondary measure, and the trial authors state the finding needs confirmation [4].
Doses studied
Most trials used 300 mg a day of the Piascledine product for 3 months to 3 years [1][2][4]. One trial of 156 participants used 600 mg a day [1].
Risks
Checked, no increase found1
Adverse events in trials
Adverse events were about as common on ASU as on placebo, 53% against 51%, in trials of people with hip or knee osteoarthritis.
The numbers and sources
- Effect
- Adverse events occurred in 53% on ASU and 51% on placebo (RR 1.04, 95% CI 0.97 to 1.12, 5 studies, 1,050 participants). Withdrawals for adverse events (17% against 15%) and serious adverse events (40% against 33%, RR 1.22, 95% CI 0.94 to 1.59) did not differ significantly in one 398-person study [1]. Another meta-analysis found no difference in adverse events (RR 1.02, 95% CI 0.83 to 1.25) [3]. A safety meta-analysis of placebo-controlled trials found ASU was not associated with higher odds of any type of adverse event [5].
- Population
- Trial participants with hip or knee osteoarthritis [1][3][5].
- Sources
- [1], [3], [5]
- Caveats
- All eligible ASU trials in the safety review allowed other osteoarthritis medicines, and its authors state that safety without them needs confirming [5].
Claims tested and not found
- That ASU slows cartilage loss. Mean joint space loss did not differ from placebo over 3 years in hip osteoarthritis [4] or across 2 studies [1].
- That ASU eases hip osteoarthritis symptoms. Pain and Lequesne index did not change significantly in hip osteoarthritis [3], and symptoms did not differ from placebo over 3 years [4].
Sources
- Cameron M, Chrubasik S. Oral herbal therapies for treating osteoarthritis. Cochrane Database of Systematic Reviews. 2014. https://doi.org/10.1002/14651858.CD002947.pub2
- Christensen R, Bartels EM, Astrup A, Bliddal H. Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials. Osteoarthritis and Cartilage. 2008. https://doi.org/10.1016/j.joca.2007.10.003
- Simental-Mendía M, Sánchez-García A, Acosta-Olivo CA, et al. Efficacy and safety of avocado-soybean unsaponifiables for the treatment of hip and knee osteoarthritis: A systematic review and meta-analysis of randomized placebo-controlled trials. International Journal of Rheumatic Diseases. 2019. https://doi.org/10.1111/1756-185X.13658
- Maheu E, Cadet C, Marty M, et al. Randomised, controlled trial of avocado-soybean unsaponifiable (Piascledine) effect on structure modification in hip osteoarthritis: the ERADIAS study. Annals of the Rheumatic Diseases. 2014. https://doi.org/10.1136/annrheumdis-2012-202485
- Honvo G, Reginster JY, Rabenda V, et al. Safety of Symptomatic Slow-Acting Drugs for Osteoarthritis: Outcomes of a Systematic Review and Meta-Analysis. Drugs and Aging. 2019. https://doi.org/10.1007/s40266-019-00662-z