Methoxyisoflavone for Sports & Fitness

Why Use


Why Do Athletes Use It?*

Some athletes say that methoxyisoflavone improves muscle mass gains from strength training without undesirable hormonal side effects.

What Do the Advocates Say?*

Methoxyisoflavone is a recently developed supplement related to the flavonoid family. Only one preliminary human trial has tested its effects on body composition changes with exercise. Although results were promising, double-blind research is needed to confirm them.

*Athletes and fitness advocates may claim benefits for this supplement based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles.

Dosage & Side Effects


How Much Is Usually Taken by Athletes?

Methoxyisoflavone is a member of the family flavonoids (isoflavones). In a U.S. Patent, the developers of this substance claim, based on preliminary animal research, that it possesses anabolic (muscle-building and bone-building) effects without the side effects seen with either androgenic (male) hormones or estrogenic (female) hormones.1 A preliminary controlled trial found that strength-training athletes who took 800 mg per day of methoxyisoflavone for eight weeks experienced a significantly greater reduction in percentage body fat than those who took a placebo.2 Double-blind research is needed to confirm these findings. The U.S. patent also claims methoxyisoflavone reduces appetite and lowers blood cholesterol levels. Whether this claim is true has not yet been demonstrated in published scientific research

Side Effects

Hormones with anabolic effects on muscle often have side effects that include acne, male-pattern baldness, prostate enlargement, and lower high-density lipoprotein (HDL; “good”) cholesterol. Whether methoxyisoflavone can cause these side effects has not been investigated.

Interactions with Supplements, Foods, & Other Compounds

At the time of writing, there were no well-known supplement or food interactions with this supplement.

Interactions with Medicines

As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.

More Resources


Where to Find It

Several substances similar to methoxyisoflavone are found in many plants and some foods, including soybeans. Whether methoxyisoflavone itself is found in nature is unknown.


See a list of books, periodicals, and other resources for this and related topics.

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