Winstrol (Stanozolol)

Overview and History of Winstrol

Winstrol is the trade name for the anabolic steroid Stanozolol. This is the third most popular and widely used anabolic steroid in all history and in the whole world. The first most popular anabolic steroid is Dianabol (Methandrostenolone), second most popular is Nandrolone Decanoate (Deca Durabolin), and the third most popular is Stanozolol. In particular, Winstrol is the anabolic steroid best known for its supposed use by Canadian Olympic sprinter Ben Johnson when he was tested positive for this compound in the 1988 Seoul Summer Olympic Games. Winstrol’s information was first documented, published, and released in 1959. Shortly thereafter, Winthrop Laboratories located in the United Kingdom manufactured it into a prescription drug for use, and in 1961 Sterling in the United States purchased the patent for the drug. Shortly thereafter, it was then released onto the North American market and given the brand name label of Winstrol.

Winstrol’s approved list of treatments for various medical conditions included: appetite stimulation for individuals suffering from tissue wasting diseases/disorders, weight maintenance and weight gain for the same conditions, strengthening of bone mass and density in Osteoporosis patients, the promotion of retarded and stunted growth in children, an adjunct medication to offset muscle wasting from long term corticosteroid administration, and for the recovery of burn victims as well as treating debilitating conditions (such as frail elderly patients). As is common with all anabolic steroids, the list of approved treatments for various medical conditions in the mid-1970s became limited and restricted by the FDA. It was then approved for a list of treatments which dwindled down to an Osteoporosis medication, and for the growth promotion in growth-retarded children.

Winstrol is one of the only anabolic steroids alongside Anavar and a couple of select others that had survived the anabolic steroid manufacturing cessation in the late 1980s and early 1990s. This anabolic steroid instead enjoyed a successful survival during the 1980s and up through the 1990s, which as a time period where pharmaceutical companies had been discontinuing the production of various anabolic steroids to a very vast degree and very quickly. During the 1990s, its use had also expanded to the treatment of Anemic patients in order to bolster red blood cell count, as well as treating Angioedema, which is a condition whereby an individual’s tissue underneath the skin swells up (often the result of hereditary genetics). Eventually, manufacturing issues caused it to be discontinued but its production was then soon after resumed by Ovation Pharmaceuticals, which purchased the rights for manufacture in 2003. Stanozolol continues to be approved for the treatment of medical conditions in North America today, but unfortunately manufacturing operations by Ovation Pharmaceuticals are not currently active. Therefore, no pharmaceutical grade related products currently exist on the American market. Internationally, Winstrol is still manufactured and marketed under several big name pharmaceutical companies, as well as generics. Winstrol is used extensively as both a human-grade product as well as a veterinary product.

Chemical Characteristics of Winstrol

Winstrol’s chemical structure differs very significantly from every other anabolic steroid. It is, however, a derivative of Dihydrotestosterone (DHT) where it contains a 3-2 Pyrazol group attached to the first cycloalkane ring (known as the A-ring) of the anabolic steroid structure. This is actually very noticeable when a picture of the chemical structure of Stanozolol is laid side-by-side with its progenitor hormone DHT, even to an individual unfamiliar with chemistry. The Pyrazol group’s attachment to the A-ring actually replaces the 3-keto group that normally sits in the same location. Specifically, this major modification classifies it as what is known as a Heterocyclic steroid.

Winstan 50This Pyrazol group, which is a functional group, is actually responsible for Winstrol’s stronger binding affinity for the androgen receptor in muscle tissue. As a DHT-derivative with modifications that separate its distinction with DHT, which is actually active in muscle tissue to a far greater degree than DHT itself is. Unfortunately, DHT itself is rendered inactive almost immediately by two enzymes upon its entrance into muscle tissue. Its modifications allow it to effectively avoid this problem. All anabolic steroids that belong to the family of DHT-derivatives (such as Winstrol, Anavar, Primobolan, Masteron and several others) contain modifications to their chemical structures that grant them significant activity and effectiveness within muscle tissue, where DHT itself unmodified would never survive metabolism there. The Pyrazol structure also grants Stanozolol a significant shift in its anabolic and androgenic strengths to favor more of a stronger anabolic strength while greatly reducing its androgenic strength. This is what grants it with an incredibly strong disassociation of anabolic to androgenic effects.

Winstrol also possesses a methyl group attached to the 17th carbon (known as C17 Alpha Alkylation), which is the chemical structural modification that allows the anabolic steroid to survive the first pass through the liver when ingested orally, and allows the anabolic steroid to become further resistant to hepatic metabolism.

Properties of Winstrol

Studies have demonstrated that Winstrol’s main mechanism of action is that of binding with cellular androgen receptors as opposed to non-receptor mediated activity (such as those possessed by Dianabol or Anadrol)[3]. It is also believed that this compound also possesses some very small measurable form of anti-Progestogenic properties in regards to the Progesterone receptor, although this is not fully understood. In addition to some small antagonistic effects on the Progesterone receptor, it has been found that it also possesses low affinity for Glucocorticoid-binding site interactions, as well as activity that is independent of Androgen receptors, Progesterone receptors, and Glucocorticoid receptors[4] [5] [6]. This androgen has not been found to have any notable Progestogenic activity in the body as well[7].

Winstrol possesses a very high binding affinity for SHBG (Sex Hormone Binding Globulin), therefore granting far more (as well as other anabolic steroids that may be stacked alongside it, such as Testosterone) to freedom in the bloodstream in doing its job of signaling muscle growth. SHBG is a protein that attaches and binds to other sex hormones (Testosterone, Estrogen, or any synthetic anabolic steroid) and renders them useless as long as SHBG is bound to that hormone. Effectively, SHBG places ‘handcuffs’ on any hormone it binds to and prevents it from doing its job. Winstrol has also demonstrated to not only prevent SHBG from binding with other anabolic steroids, but it has also demonstrated strong suppression of SHBG production in the body. For example, one particular study conducted on 25 male test subjects where Stanozolol was administered orally resulted in a 48.4% drop in SHBG levels following just 3 days of Winstrol administration[8].

With Stanozolol being a DHT-derivative, it holds the advantage that is generally associated with DHT and all other DHT-derivatives: it is unable to bind with the aromatase enzyme, which results in no possible Estrogen conversion. Resulting from this is an avoidance of the Estrogen-related side effects of water retention (and the associated risks of elevated blood pressure), as well as other Estrogen-related side effects. Being a DHT-derivative, it is also unable to interact with the 5-alpha reductase enzyme, which is the enzyme responsible for the conversion of Testosterone into Dihydrotestosterone. As its already a modified form of DHT, this cannot possibly occur.

winstrol depot ampsWinstrol exhibits a longer half-life as a result of its structural modifications, enabling the injectable format to possess a half-life of approximately 24 hours, and 9 hours for the oral preparation. In relation to Testosterone, Winstrol holds an androgenic strength rating of 30 with an anabolic strength rating of 320, which is quite significant considering this means it is slightly over three times the anabolic strength of Testosterone. In order for any individual to understand the meaning of these numbers and ratings, it must be understood that the base reference measurement for these strength ratings is the number one anabolic steroid Testosterone. Testosterone is utilized as the measuring stick or the measuring bar whereby all other anabolic steroids are referenced with and compared to (much like the celcius scale of temperature measurement where the freezing point and boiling points of water is used as the baseline measurement for temperature). Upon understanding this, any individual can easily observe how it possesses an anabolic strength of three times Testosterone (Testosterone’s anabolic and androgenic ratings are both respectively 100). Percentage-wise, it could be described that Winny is 320% more anabolic than Testosterone, and it is 30% less androgenic than Testosterone.

An important fact that must be reminded to the reader is the fact that both the injectable and oral preparations of Winstrol possess the exact same chemical structure. This is unlike nearly all other anabolic steroids, where oral preparations are always C17-alpha alkylated, and injectable preparations are absent of this methylation (and often injectable compounds are also esterified to modulate the release rate and half-life). This is not so with Stanozolol, where the oral and injectable preparations are exactly 100% identical to each other. This presents some concerns that the reader must be aware of: The result is a greater amount of hepatotoxicity (liver toxicity), and because both the injectable and oral preparations both possess the hepatotoxic modification of C17-alpha alkylation, they both will place an almost equal level of hepatotoxic strain on the liver. However, the injectable preparation avoids the first-pass through the liver, which allows it to be slightly less hepatotoxic than the oral preparation – but hepatotoxic nevertheless, and its duration of use must also have limitations placed on it.

WinstrolWinstrol (AKA Stanozolol)
Chemical Name: 17β-Hydroxy-17-methyl-5alpha-androstano[3,2-c]pyrazole
Molecular Weight: 328.49 g/mol
Original Manufacturer: 
Winthrop Laboratories
Half Life: 
9 hours (oral), 24 hours (injectable)
Detection Time: 
2 months
Anabolic Rating: 
Androgenic Rating: 


Winstrol References:

[1] Clinton R. O. et al. J. Amer chem. Soc. 81 (1959):1513

[2] U.S. Patent # 3,030,358

[3] Anabolic-androgenic steroid interaction with rat androgen receptor in vivo and in vitro: a comparative study. Feldkoren Bl, Andersson S. J Steroid Biochem Mol Biol 2005 Apr;94(5):481-7. Epub 2005 Mar 17.

[4] The differential effects of stanozolol on human skin and synovial fibroblasts in vitro: DNA synthesis and receptor binding. Ellis AJ, Cawston TE, Mackie EJ. Agents Actions. 1994 Mar;41(1-2):37-43

[5] Identification of a specific binding site for the anabolic steroid stanozolol in male rat liver microsomes. Boada LD, Fernandez L et al. J Pharmacol Exp Ther 1996 Dec;279(3):1123-9.

[6] Stanozolol and danazol, unlike natural androgens, interact with the low affinity glucocorticoid-binding sites from male rat liver microsomes. Fernandez L, Chirino R, Boada LD, Navarro D, Cabrera N, del Rio L, Diaz-Chico BN. Endocrinology. 1994 Mar;134(3):1401-8

[7] Desaulles P.A. et al. Helv. Med Acta 27 (1960), 479.

[8] Sex hormone-binding globulin response to the anabolic steroid stanozolol: Evidence for its suitability as a Biological androgen sensitivity test. G Sinnecker, S Kohler. Journal of Clin Endo Metab. 68:1195, 1989.