Nonessential Micronutrient



Livestock producers around the world are using an isoflavone (a plant chemical with “steroid-like” effects) called methoxy to naturally increase the size of their animals (hormone free), so there’s probably some potential here. Despite the claims, though, there’s just not enough evidence to show that it has any real potential for enhancing muscle size in humans. There are other more effective isoflavones, like ipriflavone (daidzein), the one methoxy’s claims are based on, which supports both your skeletal system and heart.

Other names for Methoxyisoflavone

5-methyl-7-methoxy-isoflavone, 7 methoxy, ipriflavone, methoxyflavone, methoxy

Proprietary Information

U.S. patent 4,163,746 (filed in 1977, and now expired).

Where to find Methoxyisoflavone

Methoxyflavone is a synthetic extract — a version of one of the major isoflavones, which are plant-based compounds with estrogen-like effects found primarily in soybeans.


Why athletes use Methoxyisoflavone

The claims of methoxy’s muscle-building potential are fairly exaggerated and clearly lack supporting science. Although it’s been shown and used for decades to increase the weight of barnyard animals, that doesn’t necessarily mean it works or is safe for us too. On the other hand, the isoflavone upon which methoxy was based, ipriflavone (daidzein), remains as useful as ever for the skeletal system and heart. For more information on soy isoflavones, see our nutrient profile on soy protein.

Ways that Methoxyisoflavone can enhance Muscle Gain & Recovery:
  • Potentially increase muscle mass by increasing nitrogen retention
  • Supposedly help suppress cortisol levels and spare muscle tissue
Ways that Methoxyisoflavone can enhance Fat Loss:
  • Possibly decrease fat by suppressing appetite and transporting nutrients away from fat tissue


Signs of Methoxyisoflavone deficiency

No deficiency conditions are known to exist.

Potential uses for Methoxyisoflavone

Research indicates that Methoxyisoflavone may be useful in the treatment of:

  • Catabolism (muscle wasting)
  • Pathological thinness


More about Methoxyisoflavone

Methyl-7-methoxy-isoflavone is a slightly altered version of ipriflavone (7-isopropoxyisoflavone), and because it’s considered a chemical cousin of this compound, it’s been suggested to have similar functions. But let’s get something straight right off the top: they aren’t the same, and they don’t produce the same array of benefits. Unfortunately, what’s happened as a result of this “slight” misconception is that manufacturers have allegedly used the actual science behind ipriflavone (a soy derivative also called daidzein) to make methoxy seem valid and more potent than it really is. So while ipriflavone has a more solid history of health benefits, methoxy does not share that history — in the least. Confused yet? We were… but now that we’ve scoured the research and medical journals and sorted it all out, we’ve uncovered the facts.

How it all started…

The highly touted muscle-building benefits of methoxyflavone seem to be a lot more hype than anything else, created for obvious reasons in the process of trying to obtain patents. During the search for new anabolics in the 1970’s, researchers strived to develop a compound that didn’t have the pharmaceutical steroid status. The patent for methoxyflavone (U.S. patent 4,163,746) was first filed in 1977 by Chinoin, a Hungarian pharmaceutical company and leader in flavonoid research and knowledge.

The research was aimed at finding a nutrient-repartitioning agent able to transport much-needed nutrients away from fat tissue and toward muscle tissue. Nothing much came of it, and the compound was shelved for years. Then, in the 1980’s, livestock producers introduced it as a new compound to increase lean mass in animals. Now, some 20 years later, with the end of its patent protection (which means anyone can copy the product, which is easy, since patents have to list exact manufacturing techniques), a new supplement, called methoxyisoflavone, popped onto the performance-supplement market… with no real science to back its claims.

Unfortunately, patents don’t mean a product works. They just mean the product is patented. In addition, methoxyflavones appear to have negative effects on important testosterone-conversion enzymes, whereby it inhibits the enzyme responsible for converting precursor hormones into testosterone. And, due to its similar structure to ipriflavone, it may even enhance the effects of estrogen in certain parts of the body (which isn’t in the least bit beneficial for men trying to put on muscle mass).

What did the research say — for muscle building?

Research on methoxyflavones was originally conducted in the late 1970’s (yes, as in some 20 plus years ago) and found that when methoxyflavone was given to rats, rabbits, and other barnyard animals, a small gain in bodyweight of 10% to 20% was seen. It has also been tested on emaciated, chronically ill patients and caused a gain of a few kilograms of weight. This, today, is what the main marketing claims for methoxy appear to be based on.

5-Methyl-7-methoxy-isoflavone patent research also shows that when the isoflavone is methylated, it becomes more anabolic compared to ipriflavone. This again gave marketers the idea to use substantiated ipriflavone research in their claims.

Although this research is a bit dated, it suggests, to a limited extent, that something was happening to body mass. From there, it was presumed that either catabolism (muscle wasting) had been diminished or some type of anabolic (muscle-building) action had taken place. Neither has been determined to be the effective mechanism nor documented by any conclusive studies. And the fact that there were no changes in hormone levels, except partially suppressed cortisol levels, suggested that at most, methoxyisoflavone may be a potential anti-catabolic agent (meaning it may prevent muscle breakdown).

In conclusion

Methoxy has basically no conclusive research, and its anabolic benefits are dubious and unfounded at best. Even so, livestock producers are using it to naturally increase the size of their animals (hormone free), so there’s probably some potential here. And any potential muscle-building effects of these supplements seems to occur as the result of increased calcium, potassium, and nitrogen retention, as well as by suppression of cortisol without androgenic or liver-damaging effects.

All in all, if you’re willing to roll the dice on a supplement that has more hearsay than anything else and spend the money (it’s pretty expensive), methoxy might be worth a try for muscle support. But we’ll wait for more valid research before we draw our conclusions on its real benefits.


Amount and Timing

Most manufacturers’ suggested range of 5-methyl-7-methoxy-isoflavone is anywhere between 400 and 800 mg taken in 2 divided doses (200 to 400 mg twice daily).


Part of the problem with methoxyflavone is that it becomes inert quickly, has a short half-life, and is destroyed in the stomach before it reaches the liver. Studies used injections, not oral delivery, but injection is considered a medical use and is thus illegal. And forget about protein powders claimed to contain it. If they do have any, it will be destroyed in the stomach before it enters the bloodstream. Sublingual products in a liposome delivery system appear to be the ideal form, but again this needs to be substantiated with independent studies.

Synergists of Methoxyisoflavone

Ecdysterone allegedly increases protein synthesis along with methoxy, but ecdysterone is also a questionable supplement.

Toxicity of Methoxyisoflavone

No known toxicity.

Bans and restrictions

None reported.


  • Research on methoxy is almost nonexistent. Most of the research used by manufacturers to support methoxy is actually for other isoflavones, such as ipriflavone.
  • US Patent #4163746
  • US Patent #3949085
  • Incledon, T., et al., “The Effects of 5-Methyl-7-Methoxyisoflavone on Body Composition and Performance in College-Aged Men,” Human Performance Specialists, Inc., Plantation, FL, and University of Nebraska-Kearney, Kearney, NE. (Sponsor: Jose Antonio, FACSM). Unpublished.