Tribolin was developed by the Ranvet Company, a popular veterinary drug and vitamin manufacturer in Australia. It is used specifically in horses, usually racehorses or other animals subject to strenuous straining or performance periods. Ranvet advertises it as a "powerful, triple acting anabolic combination... possessing marked anabolic properties and only a minimal amount of androgenic activity." The "triple action" and Tri in the name are not referring to the formula, as it only contains two active steroids, not three. They refer to the purported benefits of its use. The three points of drug action are stated to be the facilitation of muscular development, the offsetting of dehydration, and the aiding of protein digestion. It is commonly applied to an overworked or debilitated animal in an attempt to aid recovery, and is also used to assist in the repair of muscle, tendon, and ligament injuries. For a horse weighing approximately 1,100 pounds (500kg), a dosage of 5 ml (350 mg) is usually given every 4 to 5 weeks. Treatment would often run for 3 to 4 months. The drug is presently still available, as is the very similar Ranvet preparation Filybol Forte. Due to strict controls in Australia it is not widely available for use by athletes.
How is Tribolin Supplied
Tribolin is available on the Australian veterinary drug market. It contains 75 mg/mL of steroid in oil in a 10 mL and 20 mL vial. Filybol Forte contains 70 mg/mL of steroid in the same vial sizes.
Structural Characteristics of Tribolin
Tribolin Side Effects (Estrogenic)
Methylandrostendiol is not directly aromatized by the body, although one of its known metabolites is methyltestosterone, which can aromatize. Methlyandrostenediol is also believed to have some inherent estrogenic activity. Combined with nandrolone, which also weakly aromatizes, Tribolin is considered a weakly to moderately estrogenic steroid. Gynecomastia is possible during treatment, but generally only when higher doses are used. Water and fat retention can also become issues, again depending on dose. Sensitive individuals may need to addition an anti-estrogen such as Nolvadex® to minimize related side effects.
Tribolin Side Effects (Androgenic)
Although classified as an anabolic steroid preparation, 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 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.
Tribolin Side Effects (Hepatotoxicity)
Methylandrostenediol 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. Injectable forms of the drug may present slightly less strain on the liver by avoiding the first pass metabolism of oral dosing, although may still present substantial hepatotoxicity.
Tribolin Side Effects (Cardiovascular)
Anabolic/androgenic steroids can have deleterious effects on serum cholesterol. This includes a tendency to reduce HDL (good) cholesterol values and increase LDL (bad) cholesterol values, which may shift the HDL to LDL balance in a direction that favors greater risk of arteriosclerosis. The relative impact of an anabolic/androgenic steroid on serum lipids is dependant on the dose, route of administration (oral vs. injectable), type of steroid (aromatizable or non-aromatizable), and level of resistance to hepatic metabolism. Methylandrostenediol has a strong effect on the hepatic management of cholesterol due to its structural resistance to liver breakdown and (with the oral) route of administration. Anabolic/androgenic steroids may also adversely affect blood pressure and triglycerides, reduce endothelial relaxation, and support left ventricular hypertrophy, all potentially increasing the risk of cardiovascular disease and myocardial infarction.
To help reduce cardiovascular strain it is advised to maintain an active cardiovascular exercise program and minimize the intake of saturated fats, cholesterol, and simple carbohydrates at all times during active AAS administration. Supplementing with fish oils (4 grams per day) and a natural cholesterol/antioxidant formula such as Lipid Stabil or a product with comparable ingredients is also recommended.
Tribolin Side Effects (Testosterone Suppression)
All anabolic/androgenic steroids when taken in doses sufficient to promote muscle gain are expected to suppress endogenous testosterone production. Without the intervention of testosterone-stimulating substances, testosterone levels should return to normal within 1-4 months of drug secession. Note that prolonged hypogonadotrophic hypogonadism can develop secondary to steroid abuse, necessitating medical intervention.
Tribolin Administration (Men)
Tribolin has not been approved for use in humans. Prescribing guidelines for men are unavailable. Typical dosing schedule for physique- or performance-enhancing purposes would be in the range of 225 mg (3cc's) to 450 mg (6cc's) per week, a level that should provide quality lean mass gain without bloating or significant body fat retention.
Tribolin Administration (Women)
Tribolin has not been approved for use in humans. Prescribing guidelines for women are unavailable. Drugs containing methylandrostenediol are generally not recommended for women for physique- or performanceenhancing purposes due to its androgenic nature and tendency to produce virilizing side effects.
Due to tight controls on drug products in Australia, Tribolin and Filybol do not make it to the black market very often. The packaging is also fairly plain on both items, inviting counterfeiting. For these reasons, it is advisable to be suspicious of any Tribolin or Filybol bottle (or any Australian vet steroids for that matter) that may be found outside of legitimate channels. It is highly uncommon for volume sales of this product to be made. Unless you can personally trace these back to a legitimate supplier in Australia, they should be considered of unverified authenticity.
Newbies Research Guide reference
75mg/ml 10 and 20ml vials. This is a very interesting new veterinarian steroid from Australia. This looks like it would be a very good steroid for athletes. The Methandriol Dipropionate makes your reseptosites more prone to take up any Anabolic steroid, so you can take less with the same results.
Wlliam Llewellyn (2017) - Anabolics
Newbies Research Guide