Methenolone (also known as primobolan) was described in 1960. Squibb Company began producing injectable drug in 1962. Methenolone originally was prescribed in case of muscle loss after operations, infections, long-term illnesses, aggressive therapy with corticoids or malnutrition, and in some cases it was used to treat osteoporosis and breast cancer. Methenolone was commonly used to promote weight gain in infants, weighing less than normal, without any side effects. Methenolone is an anabolic steroid, modification of dihydrotestosterone (DHT) with weak androgenic activity and a moderate anabolic effect. A notable trait of methenolone is that it can firmly bind to androgen receptors, stronger than testosterone. Adult doses for the treatment of aplastic anemia are usually in a range of 1 - 3 mg/kg per day.

Adverse side effects include fluid and electrolyte retention, hypercalcaemia, increased bone growth and skeletal weight. In men, additional side priapism, azoospermia, hirsutism, male pattern baldness, acne andoedema. In women, side effects include virilization, amenorrhoea, menstrual irregularities, suppressed lactation, and increased libido. In children, side effects may include virilization symptoms. Metenolone may enhance effects of antidiabetics, ciclosporin, levothyroxine, warfarin. Resistance to the effects of neuromuscular blockers may occur, and metenolone also has the potential to interfere with glucose tolerance and thyroidfunction tests. Metenolone enanthate (methenolone enanthate) is an ester derivative of methenolone sold commonly under the brand names Primobolan (tablet form) orPrimobolan Depot (injectable). When it interacts with the aromatase enzyme it does not form any estrogens. It is used by people who are very susceptible to estrogenic side effects, having lowerestrogenic properties than nandrolone. This trait makes primobolan to be a good fat burner. Primobolan does not convert into estradiol.

As an anabolic steroid, the use of metenolone is banned from use in sports governed by the World Anti-Doping Agency. Belarusian shot putter Nadzeya Ostapchuk was stripped of her gold medal after testing positive for metenolone at the London 2012 Olympic Games. She has been excluded from future IOC events. The NBA and NBPA also banned the use of methenolone under the Anti-Drug Program. In February 2013, Hedo Turkoglu of the Orlando Magic was suspended for 20 games without pay by the league after testing positive for methenolone. In December 2013, Natalia Volgina was stripped of her 2013 Old Mutual Two Oceans Marathon title and received a two-year competition ban, subsequent to a final guilty verdict for using the steroid Metenolone.

Methenolone:
https://drugs.ncats.io/drug/9062ZT8Q5C

Began as a Starter Steroid:
Many beginners make first steroid experiences with methenolone. It is milder than many other steroids and has significantly fewer side effects. However, the weight gain and the increase in force are also significantly lower than by other steroids.

Metenolon was then much sought after and considered as a very mild steroid. In the end, it was not so mild and free of side effects, as we have seen today. For a long time, Metenolon was considered a starter steroid. For bodybuilders who have already had experience with stronger steroids, methenolone (neither in the acetate nor in the enatate form) is suitable neither for the build-up nor for the settling phase to maintain the muscle mass.

General experience of bodybuilders who have taken methenolone speak of a mass increase of just 3 - 4 kg in 6 weeks. The tablet version (metelonone acetate) is, however, discouraged, since the active ingredient is very poorly absorbed and is therefore no longer available for the purpose to be fulfilled. In order to achieve a better efficiency, body builders usually use the injection-variant (Methenolonenantat).

Methenolone acetate products (tablets) today come mainly from Japan and South Africa. Today, methenolonenate products (ampoules) come mainly from Mexico, Spain and Turkey.

Methenolone:
https://anabolika.de/en/methenolone

A mild nature:
Primobolan is nowhere near the most popular or powerful anabolic steroid on the market. But it is still popular, maybe for a different reason. The compound seems to hold potential for great results if used for the correct purpose. It is said to be one of Arnold Schwarzenegger's favorite steroids. You may conclude the benefits are obvious in that case if the rumors are true. Primobolan is a popular trade name of the anabolic and androgen steroid methenolone. This compound is familiar to many experienced steroid users, who often call it "Primo." It has a mild nature that makes it more tolerable to use compared to many other steroids. This drug is often compared to another popular anabolic steroid Anavar. But Primobolan is actually milder than Anavar. It has an androgenic rating between 44 and 57 and an anabolic rating of 88. Both ratings are even lower than those of testosterone.

Primobolan A Popular Steroid Amongst Athletes for Its Limited Side Effects:
https://www.gilmorehealth.com/primobolan-a-popular-steroid-amongst-athletes-for-its-limited-side-effects/

Anabolic Steroid:
Metenolone (or methenolone) is a long-acting anabolic steroid with weak androgenic (testosterone or androsterone-like) properties. It is a naturally occurring drug, found within the adrenal glands of pregnant domesticated felines, and is supplied as the acetate ester for oral administration and as the enanthate ester for intramuscular injection. Adult doses for the treatment of aplastic anemia are usually in a range of 1-3 mg/kg per day. Belongs to the class of organic compounds known as androgens and derivatives. These are 3-hydroxylated C19 steroid hormones. They are known to favor the development of masculine characteristics. They also show profound effects on scalp and body hair in humans.

Metabocard for Methenolone:
https://hmdb.ca/metabolites/HMDB0041928

What are Primobolan side effects/dangers?
Primobolan may be milder than other anabolic steroids and promise safer results; however, misuse - like with all things - can result in some pretty nasty side effects. Even though there aren't many scientific studies on the drug (aside from on rats), people who have used the steroid have reported many bad side effects. Common Primobolan side effects include: depression, acne, oily skin, hair loss/balding, excess body hair, increases in bad cholesterol, and gynecomastia (this usually only occurs if it has been stacked with another anabolic steroid). Obviously, if you keep to safe, lower dosages, the chance of these side effects happening should be minimal. However, we do advise leaning on the side of caution - especially if you are already predisposed to them e.g. you've got sensitive skin. Women especially should be careful.

Primobolan Depot Steroid (Methenolone) - Cycle, Dosage & Side Effects:
https://crazybulk.com/blog/primobolan-depot-methonolone

Primobolan Safety Data Sheet (PDF 6 pages):
https://www.caymanchem.com/msdss/17148m.pdf

Primobolan discussion:
https://thinksteroids.com/community/threads/lets-talk-about-primobolan.134381483/

Primobolan discussion:
https://canadianbrawn.com/threads/what-does-primobolan-metenolone-enanthate-do-for-you.814/

Primobolan discussion:
http://www.gymnation.co.nz/forums/topic/10131-primobolan-opinions-from-personal-experiences/

50+ results for Primobolan:
https://forums.t-nation.com/search?q=primobolan

#methenolone:
https://www.instagram.com/explore/tags/methenolone/?hl=en

Primobolan Package Leaflet (PDF 2 pages):
http://thecanadianpharm.com/images/products_images/primobolan.pdf

Metenolone esters are used mainly in the treatment of anemia due to bone marrow failure. Side effects of metenolone esters include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. Metenolone esters are synthetic androgens and anabolic steroids. They have moderate anabolic effects and weak androgenic effects, as well as no estrogenic effects or risk of liver damage. Metenolone esters were introduced for medical use in the early 1960s. In addition to their medical use, metenolone esters are used to improve physique and performance. The drugs are controlled substances in many countries and so non-medical use is generally illicit. They have mostly been discontinued for medical use and have limited availability.