Avocado Soybean Unsaponifiables

Avocado Soybean Unsaponifiables (ASU) is a natural vegetable extract, which is a combination of 1/3 avocado oil and 2/3 soybean oil. People have been using avocado or soy in traditional medicine for ages. But, it wasn’t until the 1950s that scientists started to clinically investigate the therapeutic properties of the unsaponifiable part of vegetable oils.

What is unsaponifiable?

Saponifiable is a term used to describe a matter that can be mixed with lye to make soap. Saponifiable oils, combined with lye are the basis of almost all soap products we use.

Unsaponifiable oil fractions, however, cannot form soap and, like other “good” fats, have special health benefits when ingested. The avocado portion of ASU has special properties of its own.

ASU for treating osteoarthritis

The ongoing research of the benefits of ASU is based on decades of laboratory and clinical studies.

In studies, ASU has been shown to slow the progression of osteoarthritis (OA). This natural remedy has reportedly helped many boost their joint health without the side effects of prescription and non-steroidal anti-inflammatory drugs (NSAIDs).

Osteoarthritis is the most common type of arthritis in the U.S. It is also the leading cause of long-term disability.

The extract has been studied extensively in Europe, where it is commonly used to treat OA. In 2003, a research published in the Journal of Rheumatology found ASU prevented the breakdown of cartilage and stimulated repair.

In another study ASU was shown to improve symptoms of knee osteoarthritis. This extract even eliminated the need for administering non-steroidal anti-inflammatory drugs (NSAIDs).

In the US, no prescription is required to buy ASU, which is sold as a dietary supplement for enhancing joint health.

In studies, Avocado soybean unsaponifiables took a minimum of 2 months before any improvement was noticed. An interesting fact, residual symptom relief was present for 2 months after stopping treatment.

How was ASU evaluated for treatment of osteoarthritis?

So far, four studies have been conducted to investigate the impact of ASU on knee osteoarthritis and hip osteoarthritis. Of these studies, 2 were conducted over three months – one evaluated hip and knee OA, while the other examined knee osteoarthritis only.

The third trial, which lasted for 6 months, assessed ASU on hip and knee osteoarthritis.

The fourth trial, a 2-year clinical trial assessed hip osteoarthritis.

About ASU Supplements

Only a tiny part of the entire avocados and soybeans contains oil; of that oil, only a small fraction is the unsaponifiable portion. There’s very little ASU in a handful of soybeans or a single avocado. The amount is so tiny that you couldn’t possibly consume enough of them to get an effective dose of ASU; only the supplements have enough to be medicinally useful.

The recommended daily intake is 300 mg soft gel daily for the treatment of osteoarthritis.


How does ASU benefit our health?

Since ASU is a combination of several various plant compounds, no one until now has been able to pinpoint exactly which components are most beneficial.

Based on studies that has been done with separate components, the majority of the proof points towards phytosterols, a group of fatty contents present in all plants, as the effective ingredients in ASU. Research suggests phytosterols act as modest free radical scavengers reducing the ills of oxidative stress. Additionally, plant sterols stimulate the synthesis of  substances that support cartilage health such as aggrecan, collagen,  and glycosaminoglycans. Finally, phytosterols suppress inflammation, by restricting the effectiveness of  Nuclear Factor Kappa Beta and  IL-1 Beta, two powerful catalysts of the inflammtory pathway.

ASU also contains tocopherols, the group of compounds that make up the many types of vitamin E.

One of the best features of ASU treatment is that it many users reduce their NSAID intakes. Because of the toxicity and danger these drugs offer, anything that can reduce or eliminate a person’s dependence on them should be deemed an enormous success.

A study was conducted to investigate the impact of ASU on osteoarthritis of the knees. The researchers recruited 260 adults aged between 45 – 80 years. The participants were suffering from OA of the knees and were taking NSAIDs regularly. In this double-blind placebo-controlled trial, the adults were given 300 mg or 600 mg of ASU or placebo for 3 months. There was a remarkable improvement in pain and function. The overall dosages and the number of days taking of NSAIDs in order to control pain was also reduced.

Are there side effects?

Studies suggest that side effects from Avocado Soybean Unsaponifiables are rare.  Following proper dosage may reduce chances of experiencing side effects.

Reported side effects from ASU are:

  • Indigestion
  • Constipation
  • Excessive gas or acidity
  • Diarrhea
  • Gastrointestinal irritation
  • Skin irritations such as eczema, redness
  • Headache
  • High cholesterol
  • High blood sugar level
  • Itching
  • Rashes
  • Liver damage
  • Mental confusion
  • Mouth allergy


  • Pregnant women and breastfeeding mothers should avoid taking ASU. ASU is a tested supplement. However, doctors warn pregnant and breastfeeding women against it just to be on the safe side.
  • People who are latex sensitive should not take this supplement as it may trigger acute allergic reactions. At times these allergic reactions might be very serious. To find out if the patient has latex allergy, healthcare professionals sometimes conduct a special clinical test before prescribing ASU. High blood pressure usually limits the intake of this supplement.
  • People who are taking high dose anti-inflammatory drugs should avoid taking ASU as it may trigger chemical reactions.
  • If you have skin conditions such as psoriasis, then you should consult your doctor before taking ASU. There are some severe form of skin diseases that do not go well with ASU intake. If you have a past history of any form of skin disease, you should mention that to your doctor before taking ASU.
  • If you are following a weight loss diet, you should inform your dietician before you start to take these supplements.


  • Appelboom T, Schuermans J, Verbruggen G, Henrotin Y, Reginster JY. Symptoms modifying effect of avocado/soybean unsaponifiables (ASU) in knee osteoarthritis. A double blind, prospective, placebo-controlled study. Scand J Rheumatol 2001;30(4):242-247.
  • Blotman F, Maheu E, Wulwik A, Caspard H, Lopez A. Efficacy 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. Rev Rhum Engl Ed 1997 Dec;64(12):825-834.
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