Connect
To Top


Ginkgo biloba extract raises testosterone levels?


While leafing through a bodybuilding magazine in the library, I noticed a small item concerning the effects of the popular herbal supplement, ginkgo biloba extract (GBE) on testosterone levels. For those who aren't familiar with Ginkgo, the ginkgo tree, from which the extract is derived, is often referred to as a "living fossil" because it has been around since the days when dinosaurs walked around. Numerous studies show that elements found naturally in Ginkgo, such as various flavonoids, provide some beneficial health effects. For example, GBE is known to increase blood flow and is also a potent free radical inhibitor, meaning that it inhibits out-of-control oxidation in the body. Both of these qualities can boost brain power, and ginkgo's main claim to fame is that it may help prevent the onset of dementia, and in other cases may increase brain function and alertness through an increased circulation effect. There are many other claims made for ginkgo, however. The item that I read in the bodybuilding magazine was taken from an abstract of a Chinese medical journal, and the study itself was published in Chinese. The study involved providing GBE to either normal or diabetic rats. Humans afflicted with type-2 diabetes often show low testosterone levels, and conversely, there are new studies linking the onset of both the metabolic syndrome and diabetes to low testosterone levels. The connection is that low testosterone levels promote an increased level of visceral, or deep-lying abdominal fat stores. These particular fat stores, in turn, are associated with a greater incidence of cardiovascular disease and diabetes. Sure enough, the study with rats showed that the diabetic rodents were lower in enzymes related to testosterone synthesis in the body, as well as a lower volume of cells in the Leydig cells of the testes, where testosterone is synthesized. But when diabetic rats were provided GBE for 12 weeks, most of the negative effects on testosterone synthesis were reversed or blocked. The conclusion of the study was that GBE enhanced testosterone synthesis in type-2 diabetic rats. Based on this conclusion, whoever wrote the article in the bodybuilding magazine extrapolated this study to human usage, suggesting that bodybuilders use GBE to boost testosterone levels.

There are several problems with this suggestion. For one, humans aren't rats, and what works in a rat doesn't always also work in humans. In addition, these were diabetic rats, and we do know that human diabetics tend to have lower testosterone levels, but this doesn't apply to those who don't have diabetes. Had the author of the bodybuilding article scrolled down the Pub Med page where he or she probably found the Chinese rat study, they would have found an earlier study, published in 2005 that featured human subjects. The purpose of the prior human study was to determine if using ginkgo significantly altered levels of steroid hormones, including free testosterone,cortisol, DHEA, and others. The subjects ingested 240 milligrams a day of GBE for 14 days. Before ingesting the GBE, all subjects provided baseline hormone levels for comparison purposes. The results showed that the GBE had no effect on any steroid hormones, including testosterone. This study included six men and five women, but no rats. So while GBE may indeed raise testosterone levels in diabetic rats, the odds are good that it does not provide comparable effects in humans.

The take home message from this little episode is that you should be suspicious of those who directly extrapolate animal research to humans in definitive terms. While some animal studies do prove transferable to humans, many do not. When I write my articles that involve animal research, I always end by noting that future studies  should determine if the effect shown in animals is applicable to humans. And that can only be done through studies with humans, and not just one study, either.

Learn the truth about anabolic supplements in my e-book, Natural Anabolics, available at jerrybrainum.com.

2 Comments

  1. John Rowley

    November 13, 2009 at 1:16 pm

    Jerry this is fantastic as always. Between your blog and your articles I am able to stay not only up to date but on the cutting edge!
    Thanks
    John

  2. stephan

    March 10, 2010 at 6:55 pm

    though i relize there has been a study conducted but with these six men and five woman were the blood types the same or differnt i been taking gbe now for up to a month and have noticed a uge change in vision body mass but i have also been taking 3 120 mg doesages per day

You must be logged in to post a comment Login

Leave a Reply

More in Blog Post

  • Get A Good Workout with Mike Rashid

    Muscle sensation Mike Rashid, whose motto is “Train Your Mind as Hard as You Train Your Body,” explains his shoulder massifier step...

    Cindy MamJuly 16, 2018
  • Why Your Big Toe Is Your Key To Great Calves!

    If you're looking to really build your calves, this one little piece of advice will help tremendously. Yet you rarely, if...

    Nick NilssonApril 6, 2016
  • Create Big-Ass Shoulders With Mike Rashid

    His motto “Train Your Mind as Hard as You Train Your Body,” may test your muscles and your mind.

    Iron Man MagazineMarch 21, 2016
  • The Workout and Happiness

    Happy New Year—a perennial cliché!  Can anything or anybody make you happy? To paraphrase a well-known line from Shakespeare’s Julius Caesar,...

    John BalikFebruary 11, 2015
  • New Year Resolutions

    January first, the birth of a new year.  Time to reflect on the old and plan for the new! Historically, January...

    John BalikJanuary 15, 2015
  • Do You Know Squat ?

    Have you heard any of the following recommendations? “Don’t let your knees go over your toes when you squat, because it’s...

    Doug BrignoleDecember 30, 2014
  • Another Rewarding Olympia Weekend

    A couple of weeks ago I was at the Mr. Olympia competition, the 50th rendition of that iconic event. What started...

    John BalikDecember 15, 2014
  • Muscle Beach Breakfast Club

    I have been a part of Muscle Beach Venice since competing there in the mid ’60s. Much has changed in the...

    John BalikNovember 15, 2014
  • The Science Behind My 2 Week Body Transformation into a Mythological Minotaur

    Sometimes getting in shape can mean perfect timing.  In order to make a 2 week body transformation, science can play a...

    curtis.fisherNovember 14, 2014