Mesterolone

Key takeaways

Mesterolone belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Mesterolone to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Mesterolone from memory before moving on to harder problems.

Reference excerpt

Mesterolone, sold under the brand name Proviron among others, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels. It has also been used to treat male infertility, although this use is controversial. It is taken by mouth. Side effects of mesterolone include symptoms of masculinization like acne, scalp hair loss, increased body hair growth, voice changes, and increased sexual desire. It has no risk of liver damage. The drug is a synthetic androgen and anabolic steroid and hence is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT). It has strong androgenic effects and weak anabolic effects, which make it useful for producing masculinization. The drug has no estrogenic effects. Mesterolone was first described by 1966 and introduced for medical use by 1967. In addition to its medical use, mesterolone has been used to improve physique and performance, although it is not commonly used for such purposes due to its weak anabolic effects. The drug is a controlled substance in many countries and so non-medical use is generally illicit.

Medical uses Mesterolone is used in the treatment of androgen deficiency in male hypogonadism, anemia, and to support male fertility among other indications. It has also been used to treat delayed puberty in boys. Because it lacks estrogenic effects, mesterolone may be indicated for treating cases of androgen deficiency in which breast tenderness or gynecomastia is also present. The drug is described as a relatively weak androgen with partial activity and is rarely used for the purpose of androgen replacement therapy, but is still widely used in medicine. Mesterolone is used in androgen replacement therapy at a dosage of 50 to 100 mg 2 to 3 times per day.

Non-medical uses Mesterolone has been used for physique- and performance-enhancing purposes by competitive athletes, bodybuilders, and powerlifters.

Side effects

Side effects of mesterolone include virilization among others.

Pharmacology

Pharmacodynamics Like other AAS, mesterolone is an agonist of the androgen receptor (AR). Mesterolone is described as a very poor anabolic agent due to inactivation by 3α-hydroxysteroid dehydrogenase (3α-HSD) in skeletal muscle tissue, similarly to DHT and mestanolone (17α-methyl-DHT). In contrast, testosterone is a very poor substrate for 3α-HSD, and so is not similarly inactivated in skeletal muscle. Because of its lack of potentiation by 5α-reductase in "androgenic" tissues and its inactivation by 3α-HSD in skeletal muscle, mesterolone is relatively low in both its androgenic potency and its anabolic potency. However, it does still show a greater ratio of anabolic activity to androgenic activity relative to testosterone. Mesterolone is not a substrate for 5α-reductase, as it is already 5α-reduced, and hence is not potentiated in so-called "androgenic" tissues such as the skin, hair follicles, and prostate gland. Mesterolone is not a substrate for aromatase, and so cannot be converted into an estrogen. As such, it has no propensity for producing estrogenic side effects such as gynecomastia and fluid retention. It also has no progestogenic activity. Because mesterolone is not 17α-alkylated, it has little or no potential for hepatotoxicity. However, its risk of deleterious effects on the cardiovascular system is comparable to that of several other oral AAS.

Pharmacokinetics The C1α methyl group of mesterolone inhibits its hepatic metabolism and thereby confers significant oral activity, although its oral bioavailability is still much lower than that of 17α-alkylated AAS. In any case, mesterolone is one of the few non-17α-alkylated AAS that is active with oral ingestion. Uniquely among AAS, mesterolone has very high affinity for human serum sex hormone-binding globulin (SHBG), about 440% that of DHT in one study and 82% of that of DHT in another study. As a result, it may displace endogenous testosterone from SHBG and thereby increase free testosterone concentrations, which may in part be involved in its effects.

Chemistry

Mesterolone, also known as 1α-methyl-4,5α-dihydrotestosterone (1α-methyl-DHT) or as 1α-methyl-5α-androstan-17β-ol-3-one, is a synthetic androstane steroid and derivative of DHT. It is specifically DHT with a methyl group at the C1α position. Closely related AAS include metenolone and its esters metenolone acetate and metenolone enanthate. The antiandrogen rosterolone (17α-propylmesterolone) is also closely related to mesterolone. The 17alpha-methylated analog of Mesterolone is called Demalon [2881-21-2]. The structure of mesterolone is also similar to delanterone.

History Mesterolone was developed in the 1960s and was first described by 1966. It was introduced for medical use by Schering under the brand name Proviron by 1967. The well-established brand name Proviron had previously been used by Schering for testosterone propionate starting in 1936. Following the introduction of mesterolone as Proviron, Schering continued to market testosterone propionate under the brand name Testoviron. A number of sources incorrectly state that mesterolone was synthesized or introduced for medical use in 1934.

Society and culture

Generic names Mesterolone is the generic name of the drug and its INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name, BANTooltip British Approved Name, and DCITTooltip Denominazione Comune Italiana, while mestérolone is its DCFTooltip Dénomination Commune Française.

Brand names Mesterolone is marketed mainly under the brand name Proviron.

Availability Mesterolone is available widely throughout the world, including in the United Kingdom, Australia, and South Africa, as well as many non-English-speaking countries. It is not available in the United States, Canada, or New Zealand. The drug has never been marketed in the United States.

Legal status Mesterolone, along with other AAS, is a schedule III controlled substance in the United States under the Controlled Substances Act and a schedule IV controlled substance in Canada under the Controlled Drugs and Substances Act.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Mesterolone

Start with the simplest possible case. Write down what Mesterolone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Mesterolone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Mesterolone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Mesterolone

In research: Mesterolone appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Mesterolone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Mesterolone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Androgens, Androstanes, Ketones, so understanding it makes those chapters shorter.
In everyday life: Look for Mesterolone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Mesterolone in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mesterolone means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Mesterolone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mesterolone in simple terms?

Mesterolone, sold under the brand name Proviron among others, is an androgen and anabolic steroid (AAS) medication which is used mainly in the treatment of low testosterone levels. It has also been used to treat male infertility, although this use is controversial.

Why does Mesterolone matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Mesterolone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Mesterolone.