Written by Jose Antonio, Ph.D.
06 April 2007

TU: Steady State Androgen Levels

Having trouble maintaining steady levels of blood androgen levels? Then you need to give TU (testosterone undecanoate) a much closer look. In a series of three investigations done by different groups, the role of TU was elucidated in rats, in diabetic and androgen-deficient humans, and after a surgically induced heart attack in rats. Taken together, you’ll see that TU may be one of the better androgen preparations around.

In the first investigation done at Medical University Hospital in Wuerzberg, Germany, serum testosterone was measured at baseline and in intervals over a six-week period. TU was compared to testosterone pellets that were implanted in the rats subcutaneously (below the skin). The scientists found that one injection of TU (100 milligrams per kilogram body weight) could induce high levels of testosterone for a period of four weeks while a single injection at a higher dose (500 mg/kg) can produce supra-physiological levels of testosterone for six weeks. In contrast, the testosterone pellets produce a very short-lived increase (about 14 days). Thus, for the best steady state increase in plasma testosterone, TU is excellent. (Exp Clin Endocrinol Diabetes, 2003;111:203-8)

TU: No Adverse Effects
Although androgen administration is often lambasted for producing a myriad of harmful side effects, it’s my scientific opinion that these side effects are often more hyperbole than fact (see paper by C. Street, J. Antonio, D Cudlipp, Can J Appl Physiol. 1996 Dec;21(6):421-40). Granted, as with any drug, there will be idiosyncratic effects. To expect uniformity of response is absurd.  Regardless, a study from the Medical University of Sofia (Bulgaria) examined 48 middle-aged men with type 2 diabetes, mild androgen deficiency and visceral obesity. Aside from all that, they were the picture of health! Okay, maybe not. But obviously, this is a group with a myriad of problems. And to think some wacky group of scientists would give androgens to them; lions and tigers and testosterone, oh my!

Thus, in an open label study, they gave these fine, but out-of-shape gentlemen, 120 milligrams of TU daily for three months. That’s 840 milligrams per week for a total dose of 10.1 grams. They found that TU decreased body weight significantly (-2.66 percent), waist to hip ratio (-3.96 percent), and body fat (-5.65 percent); no changes occurred in the control group. Also, TU significantly decreased blood glucose levels and mean glycated hemoglobin (HbA1c is a test that gives you an average of your blood glucose measurements). Also, and most importantly for these guys, erectile function was improved. This may be bad news for the anti-androgen lobby, but they reported no adverse effects at all (i.e., they looked at vital signs, hematological, biochemical and lipid parameters, as well).

So at least in these men, TU is safe and beneficial at relatively high dosages! (Boyanov MA et al., Aging Male, 2003;6:1-7)

TU: Heart Healthy?
You’re thinking I’m a few neurons short of coherent thought if I could actually pose the claim that TU is heart healthy, right? Things in science are most interesting when they go against the grain, against conventional wisdom. Nevertheless, scientists had adult male rats treated with either a placebo or TU, or had them orchiectomised (had their testes removed… ouch). After two weeks, animals underwent a sham operation or had the left coronary artery ligated. After coronary ligation, infarct size (the amount of dead heart tissue resulting from the artificial “heart attack”) was similar among the groups. Left ventricular hypertrophy, or growth, was enhanced by TU. On the other hand, in vivo, left ventricular end diastolic pressure and wall stress were less with TU treatment. According to the investigators, “testosterone treatment had no detrimental effects following the MI (heart attack). Reduced wall stress and left ventricular end diastolic pressure may even improve long-term outcome.”

Bottom line: Is it possible that giving TU post-heart attack might actually improve outcome? Interesting indeed. (Cardiovasc Res 2003;57:370-8)

TU: Who Needs a “Jimmy”?
They say taking steroids makes your fifth appendage shrink; you know that ain’t so, but it does make your testes the size of peanuts (while you’re on the stuff). Nonetheless, a not-so-well-known effect of testosterone administration is as a contraceptive aid. For instance, research from the National Research Institute for Family Planning in China treated hundreds of Chinese men with an initial “loading dose” of 1,000 milligrams of TU, followed by 500 milligrams TU monthly for a 12-month treatment period. They found that as a contraceptive, TU injections were 94.8 percent effective with a “failure rate” of 2.3/100 couple-years. The mean serum testosterone concentrations increased 131 percent whereas the mean serum levels of LH and FSH dropped by about 70 percent. Serum HDL levels dropped 14 percent while hematocrit increased six percent. 

According to the researchers, “the results showed that monthly TU injection at a dose of 500 milligrams after an initial loading dose of 1,000 milligrams can effectively, safely and reversibly suppress spermatogenesis in healthy Chinese men without serious adverse effects. (J Clin Endocrinol Metab, 2003;88:562-8)

Anadrol Please…
Anadrol, also known as oxymetholone, was given 50 milligrams twice daily (BID) or three times (TID) daily for 16 weeks to 89 HIV-positive women and men. Oxymetholone administration produced a 6.6-pound and 7.7-pound increase in body weight in the TID and BID groups. The placebo group gained only 2.2 pounds. Significant improvements were seen with appetite (pass me the chicken breasts!) and food intake, as well as improved well-being and what the researchers referred to as “reduced weakness by self-examination.” 

However, as with any oral androgen, there were some hepatotoxic (liver-related) effects in some individuals.  Thirty-five percent and 27 percent of the patients in the TID and BID groups had elevated alanine aminotransferase levels (indicating liver inflammation). None of the placebo patients had elevated levels. Thus, a 100-milligram or 150-milligram per day regimen of Anadrol promotes significant weight gain; however, nearly one-third of individuals may suffer from liver inflammation. Conversely, one could say that more than two-thirds of the individuals had no untoward effects. Perhaps it would be wise to get those patients who are sensitive to oral androgens to switch to a safer injectable version. (AIDS 2003, Mar, 28:699-710)