Avocado Soybean Unsaponifiables (ASU) for Osteoarthritis

ASU may slow progression of osteoarthritis

Avocado soybean unsaponifiables (often referred to as ASU) are natural vegetable extracts made from avocado and soybean oils. ASU has been shown to have beneficial effects on some symptoms of osteoarthritis and it may slow down the progression of the condition. According to the Arthritis Foundation, avocado soybean unsaponifiables are considered safe and effective for people who have osteoarthritis.

Often known by the brand name Piascledine, ASU supplements are available over the counter (OTC) as capsules that are taken by mouth.

Three avocado halves on a table
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How ASU Works

ASU contains one-third avocado and two-thirds soybean unsaponifiables—components of lipids that are unique in their composition in that they cannot be formed into soap. While the latter part of that definition seems irrelevant, it is the unique composition of unsaponifiables that is believed to be involved in its health benefits.

Interestingly, however, experts are not sure which specific chemical in this combination is the active ingredient; it could be a chemical created by the combination of ingredients as well.

The effects of ASU include the reduction of cartilage breakdown as well as the promotion of cartilage repair.

ASU decreases inflammation, and it has specifically been found to decrease the inflammatory cells and proteins that play a role in cartilage destruction in osteoarthritis.

What Research on ASU for Arthritis Shows

Eating avocado and soy, even in large amounts, does not provide enough of the unsaponifiables to induce a beneficial effect on osteoarthritis. Only a small fraction of the oil is the unsaponifiable portion.

There have been a number of human research studies and many animal studies evaluating the effect of ASU on osteoarthritis, including knee osteoarthritis and hip osteoarthritis. Results have generally been promising in terms of the improvement of symptoms, and there have been no documented side effects or safety issues.

For example, a six-month research study evaluated the effects of ASU on women who had temporomandibular joint osteoarthritis. During the trial, participants who used ASU experienced decreased pain, improved quality of life, and reported reduced use of pain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), when compared to participants who did not use ASU.

A three-year study followed a group of participants who had hip osteoarthritis. The group that used ASU had slightly less loss of joint space width than those who did not use the supplement. Decreased joint space width is measured using imaging tests, and it is widely considered a reflection of worsening osteoarthritis. No safety issues were noted over the study period.

Experts suggest that the use of ASU may also be beneficial when taken prophylactically during the early stages of osteoarthritis.

Dosage and Use

ASU supplements are available as soft gels or tablets. It is recommended that you take them with both food and water.

The recommended dose for osteoarthritis is 300 milligrams (mg) daily. There are no additional benefits noted with higher doses of avocado soybean unsaponifiables.

ASU can be taken alone or with other medications used in the treatment of osteoarthritis. The combination of ASU and glucosamine/chondroitin sulfate is widely considered safe and may enhance the effects of treatment.

It may take at least two months before you notice any improvement in your symptoms after starting ASU. You may also experience lasting symptom relief for approximately two months after you stop the treatment.

If you take ASU, be sure to include it on the list of medications you share with your healthcare provider and pharmacist. In trials, some side effects have been noted:

  • Gastrointestinal upset
  • Nausea/vomiting
  • Headaches/migraines

People with allergies to avocado and soybeans should avoid the supplement, and there have also been allergic reactions reported in people with latex sensitivity ingesting avocado-based products.

While this supplement does not have other major known side effects, it is not recommended for children, pregnant women, or anyone with a serious liver or kidney condition.

A Word From Verywell

Osteoarthritis is a degenerative condition that progresses over the years, causing pain, discomfort, and decreased mobility due to cartilage breakdown. There are a number of over-the-counter and prescription medications, supplements, exercises, physical therapy options, and lifestyle measures that can help control symptoms and slow the progression of the disease.

Currently, ASU is considered a beneficial option in the treatment of osteoarthritis, but it is not yet clear whether the benefits are long-lasting or how long a person should continue to use the supplement. Be sure to discuss any supplement that you are considering with your healthcare provider before you start taking it.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Arthritis Foundation. Avocado soybean unsaponifiables (ASU).

  2. Christiansen BA, Bhatti S, Goudarzi R, Emami S. Management of osteoarthritis with avocado/soybean unsaponifiables. Cartilage. 2015;6(1):30-44. doi:10.1177/1947603514554992

  3. Catunda IS, Vasconcelos BC, Andrade ES, Costa DF. Clinical effects of an avocado-soybean unsaponifiable extract on arthralgia and osteoarthritis of the temporomandibular joint: preliminary study. Int J Oral Maxillofac Surg. 2016;45(8):1015-1022. doi:10.1016/j.ijom.2016.01.008

  4. 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. Ann Rheum Dis. 2014;73(2):376-84. doi:10.1136/annrheumdis-2012-202485

  5. Kolasinski SL, Neogi T, Hochberg MC, et al. 2019 American College of Rheumatology/Arthritis Foundation guideline for the management of osteoarthritis of the hand, hip, and kneeArthritis Care Res. 2020;72(2):149-162. doi:10.1002/acr.24131

Additional Reading

By Carol Eustice
Carol Eustice is a writer who covers arthritis and chronic illness. She is the author of "The Everything Health Guide to Arthritis."