Winstrol is the most widely recognized trade name for the drug stanozolol. Stanozolol is a derivative of dihydrotestosterone, chemically altered so that the hormone’s anabolic (tissue-building) properties are greatly amplified and its androgenic activity minimized. Stanozolol is classified as an “anabolic” steroid, and exhibits one of the strongest dissociations of anabolic to androgenic effect among commercially available agents. It also cannot be aromatized into estrogens. Stanozolol is the second most widely used oral steroid, succeeded in popularity only by Dianabol (methandrostenolone). It is favored for its ability to promote muscle growth without water-retention, making it highly valued by dieting bodybuilders and competitive athletes.
Stanozolol was first described in 1959. It was developed into a medicine by Winthrop Laboratories in Great Britain. Parent firm (Sterling) filed for U.S. patent on the agent in 1961. Stanozolol was officially released to the U.S. prescription drug market in 1962 under the brand name Winstrol. Stanozolol was initially prescribed for a variety of medical purposes, including the induction of appetite and lean tissue gain in cases of weight loss associated with many malignant and non-malignant diseases, the preservation of bone mass during osteoporosis, the promotion of liner growth in children with growth failure, as an anti-catabolic during prolonged corticosteroid therapy or for post-operative and post-trauma (burns, fractures) patients, and even to treat debility in the elderly.
Stanozolol is a modified form of dihydrotestosterone. It differs by: 1) the addition of a methyl group at carbon 17- alpha to protect the hormone during oral administration and 2) the attachment of a pyrazol group to the A-ring, replacing the normal 3-keto group (this gives stanozolol the chemical classification of a heterocyclic steroid). When viewed in the light of 17-alpha methyldihydrotestosterone, the A-ring modification on stanozolol seems to considerably increase its anabolic strength while reducing its relative androgenicity. Stanozolol has a much weaker relative binding affinity for the androgen receptor than testosterone or dihydrotestosterone. At the same time it displays a much longer half-life and lower affinity for serum binding proteins in comparison. These features (among others) allow stanozolol to be a very potent anabolic steroid in spite of a weaker affinity for receptor binding. Recent studies have additionally confirmed that its primary mode if action involves interaction with the cellular androgen receptor. Although not fully elucidated, stanozolol may have additional (some potentially unique) properties with regard to antagonism of the progesterone receptor, Low Affinity Glucocorticoid-binding Site interaction, and AR/PR/GR independent activities. 617 618 In therapeutic doses stanozolol does not have significant progestational activity. Stanozolol is known to strongly suppress levels of SHBG (sex hormone-binding globulin). This trait is characteristic of all anabolic/androgenic steroids, although its potency and form of administration make oral Winstrol® particularly effective in this regard. One study with a group of 25 normal males demonstrated a 48.% reduction in SHBG after only 3 days of use. The dose administered was .mg/kg, or roughly 18mg for a person weighing 200lbs. Plasma binding proteins such as SHBG act to temporarily constrain steroid hormones from exerting activity in the body, and effectively reduce the available percentage of free (active) steroid. Oral stanozolol may be useful for providing a greater percentage of unbound steroid in the body, especially when taken in combination with a hormone that is more avidly bound by SHBG, such as testosterone.
Side Effects (Estrogenic):
Stanozolol is not aromatized by the body, and is not measurably estrogenic. An anti-estrogen is not necessary when using this steroid, as gynecomastia should not be a concern even among sensitive individuals. Since estrogen is the usual culprit with water retention, stanozolol instead produces a lean, quality look to the physique with no fear of excess subcutaneous fluid retention. This makes it a favorable steroid to use during cutting cycles, when water and fat retention are major concerns. Stanozolol is also very popular among athletes in combination strength/speed sports such as Track and Field. In such disciplines one usually does not want to carry around excess water weight, and may find the raw muscle-growth brought about by stanozolol to be quite favorable over the lower quality mass gains of aromatizable agents.
Side Effects (Androgenic):
Although classified as an anabolic steroid, androgenic side effects are still common with this substance. This may include bouts of oily skin, acne, and body/facial hair growth. Anabolic/androgenic steroids may also aggravate male pattern hair loss. Women are also warned of the potential virilizing effects of anabolic/androgenic steroids. These may include a deepening of the voice, menstrual irregularities, changes in skin texture, facial hair growth, and clitoral enlargement. Additionally, the 5-alpha reductase enzyme does not metabolize stanozolol, so its relative androgenicity is not affected by finasteride or dutasteride. Stanozolol is a steroid with relatively low androgenic activity in relation to its tissue-building actions, making the threshold for strong androgenic side effects comparably higher than more androgenic agents such as testosterone, methandrostenolone, or fluoxymesterone.
Side Effects (Hepatotoxicity):
Stanozolol is a c17-alpha alkylated compound. This alteration protects the drug from deactivation by the liver, allowing a very high percentage of the drug entry into the bloodstream following oral administration. C17-alpha alkylated anabolic/androgenic steroids can be hepatotoxic. Prolonged or high exposure may result in liver damage. In rare instances life-threatening dysfunction may develop. It is advisable to visit a physician periodically during each cycle to monitor liver function and overall health. Intake of c17- alpha alkylated steroids is commonly limited to 6-8 weeks, in an effort to avoid escalating liver strain. Stanozolol appears to offer less hepatic stress than an equivalent dose of Dianabol (methandrostenolone). Studies giving 12mg of stanozolol per day for 27 weeks failed to demonstrate clinically-significant changes in markers of liver function, including serum aspartate amino-transferase, alanine amino-transferase, gamma-glutamyltransferase, bilirubin, and alkaline phosphatase.
Relative hepatotoxicity increases as the dosage escalates, so hepatic dysfunction should still be a concern. In rare instances, high doses (alone or in combination with other steroids) have been implicated in cases of serious life-threatening hepatotoxicity in bodybuilders. Injectable stanozolol has also been implicated in severe hepatotoxicity in an otherwise healthy bodybuilder, and should not be used as an alternative medication when liver toxicity precludes oral stanozolol use.
The use of a liver detoxification supplement such as Liver Stabil, Liv-52, or Essentiale Forte is advised while taking any hepatotoxic anabolic/androgenic steroids.
• Molecular Weight: 344.5392
• Molecular Formula: C22H36N2O
• Melting Point:N/A
• Manufacturer: (Originally) Sterling
• Release Date:1962
• Effective Dose(men): 50-100mgs/day
• Effective Dose (women): 2.5-10mgs/day
• Active Life:8hours
• Detection Time:3 weeks (oral) to 9 weeks (injectable)
• Androgenic/Anabolic Ratio:30:320