Estrogen Blockers

Until two years ago bodybuilders who wanted to increase testosterone levels without using anabolic steroids could purchase pro-hormone supplements. The original forms of those supplements weren’t effective. For example, DHEA, an adrenal steroid produced in the human body, is used in the synthesis of other hormones, including testosterone and estrogen. Based on that, DHEA supplements were touted for increasing testosterone in bodybuilders. DHEA did do that—but only in women. In men under age 40 it was converted into either estrogen or dihydrotestosterone, a testosterone metabolite associated with acne, male-pattern baldness and prostate enlargement.

Noting the problems, several entrepreneurs scoured the scientific literature and came up with compounds that, on paper, provided more direct routes to testosterone conversion. The most popular was androstenedione, which was said to be more effective than DHEA because it was a step closer in the synthesis process: In the body DHEA converted into andro, which then converted directly into testosterone.

Andro peaked in popularity after being linked to pro baseball player Mark McGwire. During his 1998 home-run spree, which broke a Major League record, a reporter noticed a bottle of andro in his locker. McGwire didn’t deny using the supplement, noting that it was perfectly legal in baseball. He’s been evasive in denying his use of anabolic steroids.

While it would be wrong to overlook the natural ability of players such as McGwire or Barry Bonds, consider the findings of American physicist Roger Tobin of Tufts University. Tobin estimated that using anabolic steroids can help batters hit 50 percent more home runs by boosting muscle 10 percent. With 10 percent more muscle, a batter can swing about 5 percent faster, which increases the speed of the ball 4 percent as it leaves the bat. Added speed can lead to home runs 50 percent more often—up to 100 percent according to Tobin. Then again, muscle and steroids are only part of the home-run equation; there’s no shortage of muscular ball players who come nowhere near the home-run record.

But I digress. Andro was wildly popular for a while among bodybuilders. Shortly after it hit the market, I looked at the testosterone pathway and noticed that it could easily be converted into estrogen. When I said so on an Internet forum, I was accused of being “jealous” of andro’s success, but medical studies proved me right. Rather than being converted into testosterone, andro tended to take the estrogen route in men. In women, however, as with DHEA, andro did raise testosterone levels.

So it was back to the drawing board for pro-hormone purveyors. They came up with a few esoteric androgens that flew under the FDA radar for a while. None were ever definitively shown to build muscle, but some produced such side effects as acne and liver enzyme elevations.

It was left for more technically oriented supplement gurus to turn to the musty old steroid textbooks of the late 1960s and search for more effective compounds. Thousands of potential drugs were originally researched from the 1950s to the late 1960s, but most never reached the market. They were described in arcane chemical guides, most notably in Androgens and Anabolic Agents: Chemistry and Pharmacology, a 1968 tome by Julius A. Vida. Several of the compounds—nothing less than full-fledged anabolic steroids, by the way—were resurrected and released as commercial pro-hormones. But not for long. In 2005 the federal anabolic steroid law, as amended, formally prohibited them.

The last generation of pro-hormones before the ban was unquestionably the most effective. How could they not be, as they were the real thing? Nobody bothered to raise the obvious question of why the drug companies that had done all that R&D didn’t put them on the market. Two words: side effects. Most of the drugs were harder on the liver than the oral anabolics that did reach the market, and they attacked the cardiovascular system even more rapidly. To avoid liability, the manufacturers relegated them to pharmaceutical limbo.

With the demise of such effective but problematic compounds, companies turned to the only other legal means of boosting testosterone: substances that inhibit the activity of an enzyme called aromatase, which is found in such tissues as liver, brain, muscle and fat in the legs and arms, and which converts free testosterone circulating in the blood into estrogen. Aromatase may explain the failure of the first generation of pro-hormones. Even if they did raise free testosterone in the blood, it didn’t take long for aromatase to kick in and convert it into estrogen.

Bodybuilders who use anabolic steroids have long been familiar with gynecomastia, or “bitch tits,” a common side effect characterized by an accumulation of excess glandular tissue in male breasts. The culprit is an overbalance of estrogen vs. testosterone, which can also cause water retention or even interfere with brain chemistry and impede testosterone synthesis.

The original way of dealing with excess estrogen was to take tamoxifen citrate, trade name Nolvadex, which was and still is prescribed mainly for older women who have breast cancer. It’s molecularly similar to and binds to the estrogen cell receptor, thus blocking the path of actual estrogen and rendering it inert. Trouble is, Nolvadex is not only an antagonist but also an agonist of estrogen. That is, it can bind to estrogen itself. So when taken too long or in too great a dose, it interferes with testosterone synthesis.

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