Fluoxymesterone, sold under the brand names Halotestin and Ultandren among others, is a synthetic, orally active androgenic-anabolic steroid (AAS) and a 17a-alkylated derivative of testosterone developed by Pharmacia & Upjohn Company LLC, approved by FDA at 1956. Fluoxymesterone is used in the treatment of hypogonadism in males and breast cancer in women. Fluoxymesterone has a relatively high ratio of androgenic to anabolic activity similarly to testosterone. Like many 17a-alkylated AAS, it has a relatively low affinity for the androgen receptor (AR). However, its actions are mediated by the AR, most likely due to its relatively long elimination half-life of approximately 9.2 hours.

Fluoxymesterone:
https://drugs.ncats.io/drug/9JU12S4YFY

Fluoxymesterone is used to treat symptoms of low testosterone in adult men who have hypogonadism (a condition in which the body does not produce enough natural testosterone). Fluoxymesterone is used only for men with low testosterone levels caused by certain medical conditions, including disorders of the testicles, pituitary gland, (a small gland in the brain) or hypothalamus (a part of the brain) that cause hypogonadism. Fluoxymesterone is also used to stimulate puberty in men with delayed puberty. Fluoxymesterone may also be used alone or along with other medications in certain women with breast cancer that has spread to other parts of the body and can not be removed with surgery. Fluoxymesterone is in a class of medications called androgenic hormones. It works by supplying testosterone to replace the testosterone that is normally produced naturally in the body. Testosterone is a hormone produced by the body that contributes to the growth, development, and functioning of the male sexual organs and typical male characteristics. When used to treat breast cancer, testosterone works by blocking the release of estrogen to stop or slow the growth of breast cancer.

Excerpt from medlineplus.com:
https://medlineplus.gov/druginfo/meds/a682690.html

Fluoxymesterone is a man-made form of testosterone, a naturally occurring sex hormone that is produced in a man's testicles. Small amounts of testosterone are also produced in a woman's ovaries and adrenal system. Fluoxymesterone is used in men and boys to treat conditions caused by a lack of this hormone, such as delayed puberty or other hormonal imbalances. Fluoxymesterone is also used in women to treat breast cancer that has spread to other parts of the body. Fluoxymesterone treats only the symptoms of metastatic breast cancer but does not treat the cancer itself.

Excerpt from Everyday Health:
https://www.everydayhealth.com/drugs/fluoxymesterone

Fluoxymesterone is an extremely powerful anabolic androgenic steroid that was first released in the late 1950's by Upjohn under the trade name Halotestin. Shortly after, Ciba Pharmaceuticals would release the hormone under the Ultandren name, but Halotestin has remained the most recognizable brand name. When Halotestin first hit the market, it was touted as holding numerous therapeutic benefits. This extremely potent anabolic steroid was prescribed for the treatment of muscle wasting, androgen deficiency in men, lean tissue repair, malnutrition, and for healing bone fractures. It would also be regularly used to treat prolonged exposure to cortisone, paraplegia, breast cancer and often given to burn victims. Unlike many anabolic steroids, Halotestin was regularly prescribed to men and women, and while its modern day use is somewhat limited it is still used to treat breast cancer in some women. The hormone is still used to treat androgen deficiencies in some men, but it's rare and is approved for osteoporosis treatment in some postmenopausal women.

In the world of performance enhancement, Halotestin holds a reputation of being one of the most powerful and fast acting steroids on the market. However, it's not one a lot of steroid users will use. This steroid will not build a lot of mass despite a massive anabolic rating; in fact, it really won't do much at all for mass promotion. This is a steroid that is generally known as a raw strength steroid, but Halotestin is also found in some cutting cycles. It's not too uncommon for some bodybuilders to supplement with Halotestin the last few weeks before a competition. It can produce some nice conditioning effects, as well as really aid in pushing through the end of a brutal diet. However, the side effects of this steroid are no joking matter, they can be pretty harsh, and that will keep most people away.

Halotestin is not a devastating steroid when it comes to potential adverse effects, there are far worse compounds. However, it's not a compound we can call extremely user friendly, especially when we consider its hepatotoxicity and potential effects on cardiovascular health. For this reason, most will need to stay away from the compound.

Excerpt from steroid.com:
https://www.steroid.com/Halotestin.php

Halotestin is a synthetic derivative of Testosterone, but it is in particular actually a derivative of Methyltestosterone (Testosterone that has been Methylated). It is generally regarded as a very strong oral anabolic steroid that is unable to aromatize into Estrogen and also exhibits very strong androgenic strength as well. Halotestin is an incredibly colossal 19 times stronger than Testosterone itself, and its androgenic strength is a lesser but equally formidable 8.5 times the strength of Testosterone. This makes Halo an extremely potent anabolic as well as a very strong androgen - stronger than Trenbolone, which is considered the strongest conventionally and commercially available anabolic steroid available.

The issue with Halo is that of its high degree of hepatotoxicity, and through this, its high potential for altering cholesterol profiles negatively. It is for these reasons that physicians and medical professionals have elected to avoid the use of Halotestin for any treatment except for that of male androgen deficiency.

Excerpt from Steroidal.com:
https://www.steroidal.com/steroid-profiles/halotestin/

This is one of those steroids that's really only going to be useful to a select group of people who have very specific goals, and even then will probably only be used within very specific parameters, and for limited time frames. Halotestin was made by modifying testosterone with three major groups- a 17alpha-methyl group, a 11beta-hydroxy group, and a 9-fluoro group. The last group is the one that the chemical name (Fluoxymesterone) comes from. The first modification makes it able to survive oral ingestion and the first pass through the liver without being destroyed. The second modification appears to inhibit conversion to estrogen (aromatization), and the final one...well...I have no idea except to say that it appears to make it highly anabolic and also a very good target for 5a-reduction (conversion to Dihydrotestosterone). Halotestin is typically rated as being 19x as anabolic as testosterone and 8.5x as androgenic. This is all well and good, in the rodents that those ratings were determined with, but in reality, those numbers are deceiving. Nobody I know has ever taken 10 mgs of Halotestin per day and said that it produced muscle gain equal to nearly 200 mgs per day of testosterone. That's just silly, considering most people don't really gain any muscle at all off of Halotestin- although their strength (and aggression) goes up quite a bit.

For the most part, people (and I'm saying people but really, I mean "men" because women don't EVER use Halotestin) tend to use Halotestin for increasing strength and aggression in the gym or in competitions such as strongmen contests, powerlifting, or fights. Since Halo has no estrogenic activity the gains in strength that most people experience with it are very lean and not watery at all, although weight gain is virtually nil. Halotestin is basically known for increasing aggression and strength, and for being liver toxic.

On the black market, due to low demand, this is very infrequently found

Excerpt from isteroids.com:
http://www.isteroids.com/steroids/Halotestin.html

Halotestin is one of the most powerful anabolic androgenic steroids ever created with properties associated with anabolic and androgenic activity that far surpass the steroidal hormone testosterone. However, while possessing both traits its mode of action is far more anabolic and its androgenic activity does not match its structural nature. Most of the side-effects associated with Halotestin will be similar to popular DHT steroids; such negative effects can include hair-loss and acne. However, because most will only use this steroid for a very short period of time, in most cases such side-effects are of little concern. While 4 weeks of Halotestin use is common a mere 2 weeks of use is not all that uncommon at all. Granted, if we were to go past the 4 week mark the probability of negative side-effects would greatly increase but due to most understanding how toxic this steroid is to the liver most responsible users will never take such a path. Without question liver toxicity is the primary concern with this steroid; side-effects commonly associated with anabolic steroids that are estrogenic in nature do not exist with this steroid and that is comforting but the liver damage that can occur makes this one of the more dangerous steroids on the market.

It is often stated anabolic androgenic steroids increase aggression and while there is some truth to this statement it is often highly exaggerated. However, as it pertains to Halotestin here we have an anabolic androgenic steroid that does increase aggression tremendously. Aggression in of itself is not a bad thing, it is not a negative side-effect; increased aggression allows us to perform at a higher level; think of a professional athlete on the football or baseball field, if he possessed limited aggression he would be beaten down every time. Aggression becomes damaging when it is used in a negative way; Halotestin, while it will increase aggression it will not chemically alter your mind. It will not change your personality or affect your decision making or free-will. What you do and how you do it is still up to you and your responsibility alone. Even so, if you are an individual predisposed to violent behavior and outburst and you take Halotestin you are only going to increase this asinine behavior; the old saying goes, the jerk will become a bigger jerk; as for the normal and sane, he will remain normal and sane but he will now have more aggression to apply towards training and athletic performance.

Excerpt from Association Against Steroid Abuse:
https://www.steroidabuse.com/Profiles/Halotestin.html

Interactions:

Drug Interactions (77) Alcohol/Food Interactions (1) Disease Interactions (11)

What other drugs will affect Fluoxymesterone?

A total of 77 drugs are known to interact with Fluoxymesterone.

• 9 major drug interactions
  • anisindione
  • carfilzomib
  • dicumarol
  • leflunomide
  • lomitapide
  • mipomersen
  • pexidartinib
  • teriflunomide
  • warfarin
• 68 moderate drug interactions

Fluoxymesterone Drug Information:
https://www.drugs.com/cdi/fluoxymesterone.html

Some user Experiences from thinksteroids.com:
https://thinksteroids.com/community/threads/halotestin-fluoxymesterone.26099/

Halotestin Prescribing Information (PDF 12 pages):
https://pdf.hres.ca/dpd_pm/00000460.PDF

PillPack Medication Guide (PDF):
https://www.pillpack.com/medication/fluoxymesterone-tablets.pdf

Fluoxymesterone is one of the few androgen and anabolic steroid (AAS) medications that remains available for medical use in the United States. Availability of fluoxymesterone aside from the United States remains scarce, but it is marketed in some other countries such as Mexico, Moldova, and Taiwan.