Teslac is one of the very first drugs approved by the FDA to fight estrogen-dependant breast cancer, back in 1970. It does this by possibly inhibiting the aromatase enzyme in what appears to be both a noncompetitive and an irreversible manner.
I have to admit, when I first went to research this compound, I had thought I was researching a useless old Anti-Estrogen. I took a quick look at it´s chemical structure, and realized that it was actually an anabolic-steroid! Oddly, it´s D-ring (usually pictured as the upper-right hand ring in models) is a weird 6 memberes lactone ring, instead of the usual 5 ring one that testosterone has. SO& now I know it´s an anabolic steroid& but what kind? And what would it do? Primarily, it´s an Anabolic Steroid which has made it´s claim to fame by being used primarily for it´s antiestrogenic effects (much like proviron), and I think that it´s been wrongly assumed to be simply an antiestrogen by many athletes. This is not the case, and as you´ll soon see, there´s really no reason why this stuff has been pushed out of use by bodybuilders and athletes for the last decade.
The first study I looked at (1) showed that Teslac increases testosterone (by 47%) and it´s precursor androstenedione (70%) levels in the body. In the second study I looked at, it raised testosterone levels in men up to 290ng/dl (almost enough to bring you from 0 test to the lowest end of normal/acceptable range), as well as raising LH (leutenizing hormone) levels, and even FSH (Follicle Stimulating Hormone) levels slightly (2). So as you can see, not only is this stuff not suppressive of your natural hormones, it actually stimulates your body to produce more testosterone as well as the hormones which produce it.(2) As for it´s ability to halt aromatization, it has been shown to reduce it by 90-95%, with regards to decrease in the overall rate, in some instances (7). In another third study, Aromatase inhibition by testolactone, at a dose of 500 mg twice daily (so a total of 1,000mgs/day) for 4 weeks lowered circulating estradiol (E2) levels by roughly 1/3rd and enhanced the secretion of follicle-stimulating hormone and testosterone by approximately the same amount (1/3rd each)(6). Basically, we´re looking at pretty decent reductions in both aromatization, as well as reduction in total estrogen floating around your body. So far, we have seen that, in different studies it has been shown to increase LH as well as FSH, respectively, and in addition it raises testosterone levels and lowers estrogen levels in all of the studies we´ve examined. Raising FSH, LH, and testosterone while lowering estrogen is a pretty good deal considering most steroids lower endogenous (natural) production of the first three, and raise estrogen.
In fact, I´ll go so far as to say that if you don´t want to do any shots (injections) during your Post-Cycle-Therapy (PCT), Teslac may be perfect for you, since it will raise LH as well as HCG in most cases! And it has the added benefit of not desensitizing your leydig cells as much as HCG has the potential to do. Another important benefit of using Teslac over HCG during your PCT is that HCG actually may raise estrogen levels and/or act as an estrogen in certain tissues (8) (9), while we know that Teslac lowers estrogen levels and acts as (of course) an androgen.
This means, of course, if you are one of those people who are inclined to bridge (use a low dose of an anabolic compound between higher dose cycles), then this is perfect for you. In addition, you´ll be able to use Teslac during a cycle as an ancillary compound which will eliminate aromatasation.
Possibly the most exciting thing I read about Teslac is that it has been PROVEN (!) to be an effective and safe treatment for Gynocomastia(3) (development of breasts in male mammary glands& often ineloquently referred to as "bitch tits" in gym-speak). So yeah, if you get a bit of Gyno on a cycle, you may want to include Teslac in your PCT for both the (very good) reasons I revealed above, as well as it´s potential to treat your gyno.
The only prohibitive thing about Teslac is cost. Currently, I don´t know of any online pharmacies who carry it,nor UG Labs& and it generally sells for anywhere between a dollar and $5 for a 250mg tab. If there´s anything preventing this stuff from becoming the "must have" drug for PCT overnight, it´s the cost.
[17 alpha-oxa-D-homo-1,4-androstadiene-3,17-dione ]
Molecular Weight: 300.3968
Molecular Formula: C19 H24 O3
Melting Point: N/A
Release Date: 1970
Effective Dose: 250mg/.day
Active Life: up to 24hours
Detection Time: 4-6 weeks
Androgenic: Anabolic Ratio:N/A
- Vigersky RA, Glass AR. Effects of delta 1-testolactone on the pituitary-testicular axis in oligospermic men. J Clin Endocrinol Metab 1981 May;52(5):897-902
- Reversal of the hypogonadotropic hypogonadism of obese men by administration of the aromatase inhibitor testolactone.Metabolism. 2003 Sep;52(9):1126-8.
- Acta Endocrinol Suppl (Copenh). 1986;279:218-26
- Vigersky RA, Mozingo D, Eil C, Purohit V, Bruton J. The antiandrogenic effects of delta 1-testolactone (Teslac) in vivo in rats and in vitro in human cultured fibroblasts, rat mammary carcinoma cells, and rat prostate cytosol. Endocrinology 1982 Jan;110(1):214-9
- Martikainen H, Ruokonen A, Ronnberg L, Vihko R. Short-term effects of testolactone on human testicular steroid production and on the response to human chorionic gonadotropin. Fertil Steril 1985 May;43(5):793-8
- Effect of aromatase inhibition by delta 1-testolactone on basal and luteinizing hormone-releasing hormone-stimulated pituitary and gonadal hormonal function in oligospermic men.. Fertil Steril. 1985 May;43(5):787-92.
- The effects of the aromatase inhibitor delta 1-testolactone on gonadotropin release and steroid metabolism in polycystic ovarian disease.J Clin Endocrinol Metab. 1985 Apr;60(4):773-8
- Pituitary-testicular responsiveness in male hypogonadotropic hypogonadism. J Clin Invest. 1974 Feb;53(2):408-15.
- Winter JS, Taraska S, Faiman C. The hormonal response to HCG stimulation in male children and adolescents. J Clin Endocrinol Metab 1972 Feb;34(2):348 353