Avocado/Soybean Unsaponifiables (ASU)

Q: Does ASU work for hip osteoarthritis?

Less clearly than for the knee. A 2019 meta-analysis found lower pain and Lequesne scores in knee but not hip osteoarthritis, and the 3-year ERADIAS hip trial (345 analysed) found no difference in symptoms or average joint-space loss. One older 6-month trial reported a more marked effect in hips.

Q: Does ASU protect cartilage?

Not clearly. A 3-year hip trial found no difference in average joint-space loss (−0.638 vs −0.672 mm), though fewer people progressed by 0.5 mm or more (40% vs 50%).

Q: Is ASU the same as eating avocados or soybean oil?

No. ASU is a concentrated extract of the unsaponifiable fractions of the two oils, and almost all trials used one product, Piascledine 300, mostly at 300 mg/day. Eating avocados or soybean oil has not been tested as a substitute.

Q: How does it compare with chondroitin?

In a 6-month knee trial (361 evaluable patients), 300 mg/day ASU and 1,200 mg/day chondroitin sulfate gave similar improvements, with no placebo group.

Q: How does ASU compare with glucosamine?

In a 2024 single-blind knee trial of 200 people, glucosamine sulfate 1,500 mg/day improved pain and function faster at 4 weeks, but by 8 weeks Piascledine 300 mg/day did as well. There was no placebo group.

Also called ASU, Piascledine, Piascledine 300, ASU-E, avocado-soy unsaponifiables.

Best grade B across 6 graded outcomes Other Last checked Oct 21, 2026

The short answer

From 13 sources

ASU is an extract of avocado and soybean oils studied for hip and knee osteoarthritis, mostly as the product Piascledine at 300 mg a day. Manufacturer-supported trials found modest gains in pain and function, clearer for the knee than the hip. A 3-year hip trial found no difference in average joint-space loss.

Every graded outcome on this page

6 rows · line = participants

Grade BPain and function (Lequesne index) in hip or knee osteoarthritisOsteoarthritis painn 664
Grade CJoint-space narrowing in hip osteoarthritis over 3 yearsJoint structuren 345
Grade CKnee pain and function versus glucosamine sulfateOsteoarthritis painn 200
Grade CNeed for anti-inflammatory painkillers (NSAIDs)Painkiller usen 163
Grade CFunction and pain in knee or hip osteoarthritisOsteoarthritis painn 144
Grade DJoint-space narrowing in hip osteoarthritis over 2 yearsJoint structuren 108
3 more graded outcomes, in the evidence chapter

Key facts

Pooled symptom effect: 4 manufacturer-supported trials (664 patients, 300 mg/day): pain effect size 0.39 and Lequesne index effect size 0.45 versus placebo; about 6 people needed for one extra responder¹
Knee vs hip: A 2019 meta-analysis found lower pain and Lequesne scores in knee osteoarthritis but not in hip osteoarthritis²
Joint structure: ERADIAS (399 people with hip osteoarthritis, 3 years): no difference in mean joint-space loss, but fewer 'progressors' (40% vs 50%)⁷
Dose: 300 mg/day worked as well as 600 mg/day in a 3-month knee trial⁴
Side effects: Adverse events were similar to placebo in pooled trials (relative risk 1.02)²

What it is

ASU is a blend of the unsaponifiable (non-soap-forming) fractions of avocado and soybean oils, studied mainly as Piascledine 300 for osteoarthritis.

How it works

Proposed

ASU is made from the unsaponifiable fractions of avocado and soybean oils. It is classed with the symptomatic slow-acting drugs for osteoarthritis, with effects described as appearing after about 2 months and persisting after stopping. How it acts on cartilage in people is not established.^3,9

Forms

Form

The form on this page
Form	Elemental %	Absorption (human data)	GI tolerance	Studied for
Piascledine 300 (ASU-E) capsule	Varies^1,7Not applicable (whole compound or extract; no elemental fraction)	Not reported in the cited abstracts.⁷	Safety described as excellent over 3 years at 300 mg/day; adverse events similar to placebo in pooled trials.^2,7	Hip and knee osteoarthritis symptoms and joint structure

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

6 graded outcomes, largest study first

6 graded outcomes: 3 improved, 1 mixed, 2 no effect. The largest, a 2008 meta-analysis of 664 people on pain and function (Lequesne index) in hip or knee osteoarthritis, found an improvement.

By sizeTable

1Pain and function (Lequesne index) in hip or knee osteoarthritis

Improved · Grade B · Meta-analysis, 664 people, 2008

4 randomised trials in hip (41%) or knee (59%) osteoarthritis

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Pain and function (Lequesne index) in hip or knee osteoarthritis	Improved	664	Grade B · Meta-analysis, 2008	4 randomised trials in hip (41%) or knee (59%) osteoarthritis
Joint-space narrowing in hip osteoarthritis over 3 years	Mixed	345	Grade C · RCT, 2014	Adults with symptomatic hip osteoarthritis (399 randomised, 345 analysed)
Knee pain and function versus glucosamine sulfate	No effect	200	Grade C · RCT, 2024	Adults with knee osteoarthritis (Vietnam), mean age 58.5
Need for anti-inflammatory painkillers (NSAIDs)	Improved	163	Grade C · RCT, 1997	Adults with knee or hip osteoarthritis needing NSAIDs
Function and pain in knee or hip osteoarthritis	Improved	144	Grade C · RCT, 1998	164 adults with knee (114) or hip (50) osteoarthritis; 144 evaluable at 6 months
Joint-space narrowing in hip osteoarthritis over 2 years	No effect	108	Grade D · Pilot RCT, 2002	Adults with hip osteoarthritis (163 randomised, 108 radiologically evaluable)

Every graded row

6 rows

Form tested

Showing 6 of 6 outcomes. Human trials only.

Grade BPain and function (Lequesne index) in hip or knee osteoarthritisOsteoarthritis painEffect size 0.39–0.45Meta-analysis · 4 studies
n 664 · 2008

Improved Pain favoured ASU (effect size 0.39, 95% CI 0.01–0.76, I² 83.5%) as did the Lequesne index (effect size 0.45, 0.21–0.70). Responders: odds ratio 2.19, number needed to treat 6 (4–21). Results favoured knee over hip.

Design: Meta-analysis, 4 studies, n = 664, 2008
Population: 4 randomised trials in hip (41%) or knee (59%) osteoarthritis
Form: ASU 300 mg vs placebo
Dose: 300 mg/day
Duration: 3–12 months (average 6)
Source: Reference 1 · PubMed 18042410 (opens PubMed)

Grade CJoint-space narrowing in hip osteoarthritis over 3 yearsJoint structureMean loss unchangedRCT
n 345 · 2014

Mixed Mean joint-space loss did not differ (−0.638 vs −0.672 mm, p = 0.72), but fewer patients progressed by ≥ 0.5 mm (40% vs 50%, p = 0.040). Clinical outcomes did not differ.

Design: RCT, n = 345, 2014
Population: Adults with symptomatic hip osteoarthritis (399 randomised, 345 analysed)
Form: ASU-Expanscience (Piascledine) vs placebo
Dose: 300 mg/day
Duration: 3 years
Source: Reference 7 · PubMed 23345601 (opens PubMed)

Grade CKnee pain and function versus glucosamine sulfateOsteoarthritis painNo effectRCT
n 200 · 2024

No effect Pain (VAS) fell from 49.3 to 37.6 mm at 4 weeks and 25.3 mm at 8 weeks with Piascledine. Glucosamine improved VAS and WOMAC more at 4 weeks; by 8 weeks the groups did not differ. Side effects in 16.0% (nausea 10.0%); BMI and lipids were not meaningfully changed.

Design: RCT, n = 200, 2024
Population: Adults with knee osteoarthritis (Vietnam), mean age 58.5
Form: Piascledine vs glucosamine sulfate 1,500 mg/day (no placebo)
Dose: 300 mg/day
Duration: 8 weeks
Source: Reference 11 · PubMed 39981153 (opens PubMed)

Grade CNeed for anti-inflammatory painkillers (NSAIDs)Painkiller useImprovedRCT
n 163 · 1997

Improved Fewer people restarted NSAIDs with ASU (43.4%) than with placebo (69.7%, P < 0.001); function improved more (−2.3 vs −1.0, P < 0.01), but pain scores were similar.

Design: RCT, n = 163, 1997
Population: Adults with knee or hip osteoarthritis needing NSAIDs
Form: ASU vs placebo (with NSAIDs for the first 45 days)
Dose: One capsule per day
Duration: 3 months
Source: Reference 5 · PubMed 9476272 (opens PubMed)

Grade CFunction and pain in knee or hip osteoarthritisOsteoarthritis painImprovedRCT
n 144 · 1998

Improved Lequesne index fell from 9.7 to 6.8 with ASU vs 9.4 to 8.9 with placebo (P < 0.001); pain fell from 56.1 to 35.3 mm vs 56.1 to 45.7 mm (P = 0.003). Success rate 39% vs 18%; effects persisted 2 months after stopping.

Design: RCT, n = 144, 1998
Population: 164 adults with knee (114) or hip (50) osteoarthritis; 144 evaluable at 6 months
Form: ASU vs placebo
Dose: Not stated in the abstract
Duration: 6 months, plus 2-month follow-up
Source: Reference 3 · PubMed 9433873 (opens PubMed)

Grade DJoint-space narrowing in hip osteoarthritis over 2 yearsJoint structureNo effectPilot RCT
n 108 · 2002

No effect No overall difference in joint-space loss (intergroup p = 0.9) and no difference in clinical outcomes. A post-hoc analysis found less narrowing with ASU in the half of patients with the narrowest joints.

Design: Pilot RCT, n = 108, 2002
Population: Adults with hip osteoarthritis (163 randomised, 108 radiologically evaluable)
Form: ASU vs placebo
Dose: Not stated in the abstract
Duration: 2 years
Source: Reference 6 · PubMed 11932878 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

Modest, mostly knee, mostly one maker

The symptom benefit is small to moderate, clearer in knee than hip osteoarthritis, and rests on trials supported by the manufacturer.^1,2

Structure claims are not proven

Both hip-structure trials missed their main outcome; only secondary or post-hoc analyses favoured ASU.^6,7

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 300 mg/day (most trials, up to 3 years) to 600 mg/day, which did no better than 300 mg/day in a 3-month knee trial. These are research doses, not recommendations.^1,4,7

When trials measured an effect

2 outcomes

How long trials ran before effects were measured
Outcome	Measured at	Basis
Pain and function (Lequesne index)	From month 2 versus placebo; effect persisted 2 months after stopping	6-month placebo-controlled trial in 164 adults with knee or hip osteoarthritis³
Knee pain (within-group)	Lower at week 4, lower still at week 8	Piascledine 300 mg/day arm of a 200-person trial against glucosamine (no placebo)¹¹

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

Interactions

0 agents

None found in our sources.

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Avocado/Soybean Unsaponifiables and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Avocado/Soybean Unsaponifiables.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

4 groups

People using NSAIDs or other osteoarthritis medicines: Every ASU trial in a 2019 safety meta-analysis allowed other osteoarthritis medicines alongside it, so the reviewers said the safety of ASU on its own still needs confirming in trials without those medicines.⁹
People with digestive complaints: Gastrointestinal effects were the most common adverse events reported for ASU in post-marketing studies.¹⁰
Reflux, hiatal hernia or swallowing problems: A 2019 case report described lipoid pneumonia (lipid in the lungs) in an 83-year-old with a hiatal hernia and reflux who had taken Piascledine capsules for 20 years; the authors called it the first such case reported.¹²
Pregnancy, breastfeeding and children: No reliable data: the cited trials enrolled adults with osteoarthritis, and LactMed has no entry on ASU, so there are no data for pregnancy, breastfeeding or children.^3,7

Tolerability

2 notes

Similar to placebo in trials.

Pooled trials: Adverse events were similar with ASU and placebo (relative risk 1.02, 95% CI 0.83–1.25).²
Post-marketing: Gastrointestinal adverse events were the most commonly reported in post-marketing cohort studies.¹⁰

How to read the label

What to check on the Supplement Facts panel.

How to read the label

2 checks

Not every 'ASU' is Piascledine

Almost all trial data come from one proprietary product, Piascledine 300 (ASU-E). Other ASU blends may differ in composition.^7,9

Label dose vs studied dose

Trials used 300 mg/day; 600 mg/day gave no extra benefit in a 3-month knee trial.^1,4

Have the bottle? Photograph its Supplement Facts panel and see each line, avocado/soybean unsaponifiables (asu) included, beside the doses and forms the trials used in Label X-Ray.

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

6 answers

Does ASU work for hip osteoarthritis?

Less clearly than for the knee. A 2019 meta-analysis found lower pain and Lequesne scores in knee but not hip osteoarthritis, and the 3-year ERADIAS hip trial (345 analysed) found no difference in symptoms or average joint-space loss. One older 6-month trial reported a more marked effect in hips.^2,7,3

Does ASU protect cartilage?

Not clearly. A 3-year hip trial found no difference in average joint-space loss (−0.638 vs −0.672 mm), though fewer people progressed by 0.5 mm or more (40% vs 50%).⁷

Is ASU safe?

Adverse events were similar to placebo in pooled trials (relative risk 1.02). Stomach upset is the most common complaint; nausea affected 10% in a 2024 trial. A single case report describes lipoid pneumonia after 20 years of use in a person with reflux.^2,10,11,12

Is ASU the same as eating avocados or soybean oil?

No. ASU is a concentrated extract of the unsaponifiable fractions of the two oils, and almost all trials used one product, Piascledine 300, mostly at 300 mg/day. Eating avocados or soybean oil has not been tested as a substitute.^1,7,9

How does it compare with chondroitin?

In a 6-month knee trial (361 evaluable patients), 300 mg/day ASU and 1,200 mg/day chondroitin sulfate gave similar improvements, with no placebo group.⁸

How does ASU compare with glucosamine?

In a 2024 single-blind knee trial of 200 people, glucosamine sulfate 1,500 mg/day improved pain and function faster at 4 weeks, but by 8 weeks Piascledine 300 mg/day did as well. There was no placebo group.¹¹

Sources

13 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

13 sources

1Symptomatic efficacy of avocado-soybean unsaponifiables (ASU) in osteoarthritis (OA) patients: a meta-analysis of randomized controlled trials.Meta-analysis Osteoarthritis Cartilage, 2008 · PMID 18042410
2Efficacy 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.Meta-analysis Int J Rheum Dis, 2019 · PMID 31328413
3Symptomatic efficacy of avocado/soybean unsaponifiables in the treatment of osteoarthritis of the knee and hip: a prospective, randomized, double-blind, placebo-controlled, multicenter clinical trial with a six-month treatment period and a two-month followup demonstrating a persistent effect.RCT Arthritis Rheum, 1998 · PMID 9433873
4Symptoms modifying effect of avocado/soybean unsaponifiables (ASU) in knee osteoarthritis. A double blind, prospective, placebo-controlled study.RCT Scand J Rheumatol, 2001 · PMID 11578021
5Efficacy and safety of avocado/soybean unsaponifiables in the treatment of symptomatic osteoarthritis of the knee and hip. A prospective, multicenter, three-month, randomized, double-blind, placebo-controlled trial.RCT Rev Rhum Engl Ed, 1997 · PMID 9476272
6Structural effect of avocado/soybean unsaponifiables on joint space loss in osteoarthritis of the hip.Pilot RCT Arthritis Rheum, 2002 · PMID 11932878
7Randomised, controlled trial of avocado-soybean unsaponifiable (Piascledine) effect on structure modification in hip osteoarthritis: the ERADIAS study.RCT Ann Rheum Dis, 2014 · PMID 23345601
8Efficacy and safety of piascledine 300 versus chondroitin sulfate in a 6 months treatment plus 2 months observation in patients with osteoarthritis of the knee.RCT Clin Rheumatol, 2010 · PMID 20179981
9Safety of Symptomatic Slow-Acting Drugs for Osteoarthritis: Outcomes of a Systematic Review and Meta-Analysis.Meta-analysis Drugs Aging, 2019 · PMID 31073924
10Safety of Anti-osteoarthritis Medications: A Systematic Literature Review of Post-marketing Surveillance Studies.Systematic review Drugs, 2025 · PMID 40095377
11The Efficacy of Piascledine in Alleviating Symptoms and Its Impact on Blood Lipid Levels and body Mass Index in Patients with Knee Osteoarthritis.RCT Med Arch, 2024 · PMID 39981153
12A case report of exogenous lipoid pneumonia associated with avocado/soybean unsaponifiables.Observational BMC Pulm Med, 2019 · PMID 31795982
13Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis.Meta-analysis Br J Sports Med, 2018 · PMID 29018060

What changed

Every dated change to this page: what changed, who made it and why.

Change log

3 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026evidence, time to effect, who should avoid, FAQ, questions, related	Added a 2024 200-person knee trial comparing Piascledine with glucosamine sulfate (no difference at 8 weeks; grade C), the 2019 and 2018 meta-analysis results in the evidence notes, time-to-effect rows, a 2019 case report of lipoid pneumonia after 20 years of use in a person with reflux, a cited pregnancy note, page questions and the bones-and-joints goal hub. Replaced FAQ items that duplicated the page's own questions. Interactions checked in LiverTox, LactMed, NCCIH and MedlinePlus (no ASU entry in any) and PubMed (only a 1991 report of avocado fruit lowering warfarin's effect, not ASU), so the list stays empty. Searched PubMed for 2023–2026 meta-analyses and trials: none newer besides the 2024 trial; not added: a 14-person 2016 jaw-joint pilot trial.	Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md
Oct 14, 2026all	Independent adversarial review: corrected the NSAID line to match the 2019 safety meta-analysis, which said ASU's safety without other osteoarthritis medicines still needs confirming.	Writer: Kymata Health EditorialTrigger: review
Oct 14, 2026all	Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record, none retracted) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice.	Writer: Kymata Health EditorialTrigger: new page

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