The Royal Jelly testosterone factor – part 2

Yesterday we wrote about an Iraqi animal study in which Royal Jelly boosted the testosterone level. Researchers at the New York Medical College discovered back in the 1980s that Royal Jelly contains testosterone. A little. So little that it can’t explain the effects that the Iraqis report.

Royal Jelly is a concentrate that makes queen bees live 60 times as long as ordinary bees. In almost every culture that keeps bees healers have found a use for this wonder jelly. In Kampo, traditional Chinese medicine, Royal Jelly is used to treat menopause problems. The Kampo tradition inspired Japanese researchers to study whether Royal Jelly can help against osteoporosis. [Evid Based Complement Alternat Med. 2006 Sep; 3(3): 339-48.]

The researchers removed ovaries from female rats and thus stopped estradiol production. [OVX] Then they gave the rats feed for 7 weeks that contained 0.5 [RJ1] or 2 percent [RJ2] Royal Jelly. Other groups were given the same quantities of Royal Jelly, but from a preparation that had been pre-treated with a protein-splitting enzyme. [pRJ] The bone-strengthening effect of the supplement is pretty close to that of synthetic estradiol.


The Japanese suspect that Royal Jelly contains a hormone that keeps bones strong. A well-known hormone, even: “Since Royal Jelly contains a male hormone testosterone, this agent may also be effective in men’s osteoporosis that could be induced by a decrease of androgen”, they write.

In 1984 endocrinologists at New York Medical College announced that they had indeed found testosterone in Royal Jelly. [Experientia 40 1984 104-6.] But as you can see in the table below, we’re talking about nanograms. To make it clear: a nanogram is a millionth of a milligram.


Testosterone surge
Such a miniscule amount of hormone can’t possibly have the effects attributed to it in the studies. Like the graph below. This shows the concentration of testosterone in male rabbits during the summer.


The figure is from a recent Egyptian study. [Anim Reprod Sci. 2010 Aug;121(1-2):174-80.] In Egypt rabbit is an important source of meat, but the climate is really to hot for them. The heat makes male rabbits infertile in the summer. In the article the researchers, working at Alexandria University, describe their successful attempt to boost testosterone and sperm production by giving the animals Royal Jelly.

What’s interesting in the Egyptian study is the doses they used. The researchers gave their overheated rabbits 200, 400 or 800 mg Royal Jelly per kg bodyweight, in an oral form just once a week. The experiment lasted 6 weeks.

This stuff isn’t interesting. It’s fascinating: an oral substance that has an ergogenic effect if you take it just once a week. More about this soon.

Royal jelly counteracts bucks’ “summer infertility”


Exposure of male rabbits to heat stress during summer adversely affects their fertility leading to major production losses. A total number of 24 male rabbits were randomly divided into four experimental groups exposed to temperatures ranging from a high of 32 degrees C to a low of 23 degrees C. Animals of the 2nd, 3rd and 4th group were individually orally given 200, 400, or 800 mg royal jelly (RJ)/kg body weight once a week to evaluate the ability of RJ feeding to counteract “summer infertility” in bucks and enhance their physiological status. Royal jelly treatments significantly boosted testosterone level to 133, 143 and 124% of basal, increased ejaculated volume by 36, 31 and 18%, increased seminal plasma fructose to 122, 124, and 111%, improved sperm motility by 15, 18 and 5%, increase sperm total output by 65, 63 and 35%, reduced abnormal sperm by 24, 24 and 15% and dead sperm by 27, 25 and 17% compared to the heat stressed control animals. Serum total protein, albumin and globulin increased while serum total lipids, cholesterol and triglycerides decreased with RJ treatments. Creatinine was reduced by 5, 13 and 8% and uric acid by 4, 7 and 4%, respectively for the three doses of RJ compared to control. Alkaline phosphatase has significantly increased to reach 114, 118, and 108% of heat stressed level with the three doses of RJ, indicating the occurrence of active bone deposition. Glucose level increased significantly to reach 105, 112, and 116% of heat stressed control and both calcium and phosphorus increased significantly with RJ treatments. It was concluded that royal jelly administration to heat stressed male rabbits can counteract their “summer infertility” and improve their physiological status.

PMID: 20538419 [PubMed – indexed for MEDLINE]