1-Testosterone (1-T) is an anabolic steroid structurally related (but not identical) to testosterone. It is one of the many byproducts of the body’s normal processing of steroid hormones.

1-T was discovered in the 1950s, explored as a potential anabolic product by the pharmaceutical company G.D. Searle, but not developed. The potency of this compound was shown in a 1961 study, and a metabolic study was published in 1972, but these received little attention. In the 1990s governments worldwide adopted police-state tactics to eliminate people’s access to anabolic steroids, thereby creating a strong incentive for finding alternative muscle-building enhancers. This led to the rediscovery by Patrick Arnold of 1-Testosterone, 1-Androstenedione, and other long-forgotten compounds that (in some countries, at least) were not covered by anti-steroid laws.

Typical claims made for 1-Testosterone

(1) 7 times the anabolic potency of testosterone
(2) High oral bioavailability
(3) Long plasma half-life
(4) Well absorbed through the gut
(5) Ether and ester forms are absorbed through the lymphatic system, bypassing the liver
(6) Is not a prohormone; is efficacious in its own right
(7) Is not converted to estrogen in the body, therefore causes no breast enlargement or water retention
(8) No conversion into DHT in the body, therefore won’t cause acne, scalp-hair loss, or body/facial hair growth
(9) No liver damage, stomach discomfort, or toxicity
(10) No side effects
(11) Increases lean muscle mass, strength, muscle hardness and vascularity
(12) Decreases body fat

Typical claims made against 1-Testosterone

(13) Is dangerous
(14) Causes breast enlargement
(15) Causes clitoral enlargement
(16) Causes testicles to shrink
(17) Causes infertility in males
(18) Causes acne, scalp hair loss, body/facial hair growth
(19) Causes voice deepening
(20) Causes prostate cancer, liver tumors
(21) Causes increased aggression, mood swings
(22) Causes tendon ruptures
(23) Decreases libido
(24) Stunts growth
(25) Is contaminated with illegal steroid metabolites

The known facts about 1-Testosterone

• Gram for gram, 1-T has about 7.7 times the anabolic potency as testosterone, as measured by the standard protocol in rats.
• 1-T has about 20% oral bioavailability compared with less than 5% for testosterone. The bioavailability may improve if esters or ethers of 1-T are used, or if 1-T is consumed in combination with solubility enhancers, such as oils.
• The plasma half-life of 1-T has not been measured, but it is known to be considerably longer than that of testosterone (which is about 2 hours).
• 1-T does not get metabolized to estrogens, hence it will not cause breast enlargement or estrogen-related water retention.
• The conversion of 1-T to DHT is very small or nonexistent; therefore, it is unlikely to cause acne, scalp-hair loss, or body/facial hair growth.
• The concept that esters or ethers of 1-T can bypass the liver when taken orally (claim 5) is based on analogies with other steroids. The degree to which this is true remains to be seen.
• Oral use of 1-T has resulted in no reports of stomach discomfort, liver damage, or other unwanted side effects. But no formal studies of these issues have been done.
• Claim 11 — that 1-T supplementation increases lean muscle mass, strength, and vascularity — is strongly supported by reports from users. A compound with the anabolic properties of 1-T would certainly be expected to have these effects.
• There is not yet any convincing evidence for Claim 12 — that 1-T decreases body fat.
• 1-T appears to be safe, at least with short-term use.
• None of the claims 13-24 listed above against 1-T is supported by any evidence. Most of these claims come from government and sports officials, and are simply mindless regurgitations of the same claims they have made in the past about other anabolic steroids. The unique properties of 1-T make it unlikely that the side effects claimed could occur, even with long-term use.
• Claim 25 — that 1-T products are all contaminated with illegal steroids — appears to be the work of a company selling products in competition with 1-T. (Certainly small amounts of contamination might exist — virtually all products are contaminated with illegal substances if you examine them closely enough. For example, all meat products are “contaminated” with testosterone and other steroids; and you could undoubtedly find a few molecules of cocaine, heroin, or other illegal drugs in many of the products you buy, if you subjected them to rigorous enough testing, since small quantities of these substances occasionally get spilled and are picked up by the wind and blown all over the landscape. But claims of significant contamination are simply lies.)

Usage

The dosage regimen usually recommended for 1-T is 150 to 300 mg/day, divided into several spaced doses. The effective dosage may, however, depend upon bodyweight. A friend of the author of this article, a male weighing 76 kg (168 lbs), began using 300 mg/day of 1-T and started seeing increases in muscle size and strength in less than a week.

Interaction with other substances

The enzymes that perform the final breakdown of 1-T and its metabolites, preparing them for disposal in the urine, are the same enzymes that act upon many other compounds in the body. The potential therefore exists for interactions between 1-T and these other compounds. Although this aspect of the metabolism of 1-T has not yet been studied, it is likely that one of the enzymes involved is CYP3A4. CYP3A4 is an enzyme that metabolizes testosterone and other steroids, drugs such as cimetidine, ketoconazole, Viagra, and erythromycin, and components of grapefruit juice (such as quercetin). Therefore, the use of 1-T in combination with any of these other substances is likely to slow the breakdown of both substances in the body. This could be considered desirable or undesirable, depending upon the circumstances.