Testosterone enanthate

Key takeaways

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

Reference excerpt

Testosterone enanthate is used in the treatment of low testosterone levels in men. It is also used in hormone therapy for transgender men. It is given by injection into muscle or subcutaneously usually once every one to four weeks. Side effects of testosterone enanthate include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire. 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). Testosterone enanthate is a testosterone ester and a long-lasting prodrug of testosterone in the body. Because it is a prodrug of testosterone, the testosterone it releases is bioidentical to the body's own hormone, which makes it useful for producing masculinization and suitable for androgen replacement therapy. Esterase enzymes break the ester bond in testosterone enanthate, releasing free testosterone and enanthic acid through hydrolysis.

This process ensures a sustained release of testosterone in the body. Testosterone enanthate was introduced for medical use in 1954. Along with testosterone cypionate, testosterone undecanoate, and testosterone propionate, it is one of the most widely used testosterone esters. In addition to its medical use, testosterone enanthate is used to improve physique and performance. The drug is a controlled substance in many countries and so non-medical use is generally illicit.

Medical uses

Testosterone enanthate is used primarily in androgen replacement therapy. It is the most widely used form of testosterone in androgen replacement therapy. The medication is specifically approved, in the United States, for the treatment of hypogonadism in men, delayed puberty in boys, and breast cancer in women. It is also used in masculinizing hormone therapy for transgender men.

Side effects

Side effects of testosterone enanthate include virilization among others. Approximately 10 percent of testosterone enanthate will be converted to 5α-dihydrotestosterone in men without endocrine disease or taking medication that disrupts this conversion, such as finasteride. 5α-Dihydrotestosterone (DHT) can promote masculine characteristics in both males and females. These masculine characteristics include: clitoral hypertrophy, androgenic alopecia, growth of body hair and deepening of the vocal cords. Dihydrotestosterone also plays an important role in male sexual function and may also be a contributing factor of ischemic priapism in males as shown in a study conducted on the use of finasteride to treat ischemic priapism in males. Testosterone enanthate can also lead to an increase in IGF-1 and IGFBP. Testosterone enanthate can also be converted to estradiol (E2) by the aromatase enzyme, which may lead to gynecomastia in males. Aromatase inhibitors, such as anastrozole, letrozole, exemestane, etc., can help to prevent the subsequent estrogenic activity of testosterone enanthate metabolites in the body.

Pharmacology

Pharmacodynamics

Testosterone enanthate is a prodrug of testosterone and is an androgen and anabolic–androgenic steroid (AAS). That is, it is an agonist of the androgen receptor (AR). Testosterone enanthate is converted by the body to testosterone that has both androgenic effects and anabolic effects; still, the relative potency of these effects can depend on various factors and is a topic of ongoing research. Esterase enzymes break the ester bond in testosterone enantate, releasing free testosterone and enanthic acid through hydrolysis. This process ensures a sustained release of free bioavailable and bioactive testosterone in the body. Testosterone can either directly exert effects on target tissues or be metabolized by the 5α-reductase enzymes into 5α-dihydrotestosterone (DHT) or aromatized to estradiol (E2). Aromatization in this context is the process where testosterone is converted to estradiol (E2) by the enzyme aromatase (CYP19A1 in humans). This conversion involves changing the structure of testosterone to include an aromatic ring A of a steroid nucleus, making it an estrogen, a so-called female hormone, which plays various roles in the body, such as regulating reproductive functions and bone density. If not aromatized (not converted into an estrogen), both testosterone and DHT are bioactive and bind to an androgen receptor; however, DHT has a stronger binding affinity than testosterone and may have more androgenic effect in certain tissues (such as prostate gland, skin and hair follicles) at lower levels.

Pharmacokinetics Testosterone enanthate has an elimination half-life of 4.5 days and a mean residence time of 8.5 days when used as a depot intramuscular injection. It requires frequent administration of approximately once per week, and large fluctuations in testosterone levels result with it, with levels initially being elevated and supraphysiological. When testosterone enanthate is dissolved in an oil (such as castor oil), the oil acts as a depot, or reservoir, that slowly releases the drug into the bloodstream. This slow release is due to the oil's viscosity and the gradual breakdown of the ester bond by esterase enzymes. The oil creates a barrier that slows the diffusion of testosterone enanthate into the surrounding tissues, resulting in a more controlled and prolonged release compared to injecting pure testosterone enanthate. The rate at which testosterone enanthate is released from oils can vary based on the oil's viscosity and other properties such as drug solubility in the oil.

Chemistry

Testosterone enanthate, or testosterone 17β-heptanoate, is a synthetic androstane steroid and a derivative of testosterone. It is an androgen ester; specifically, it is the C17β enanthate (heptanoate) ester of testosterone.

History Testosterone enanthate was described as early as 1952 and was first introduced for medical use in the United States in 1954 under the brand name Delatestryl.

Society and culture

Generic names Testosterone enanthate is the generic name of the drug and its USANTooltip United States Adopted Name and BANTooltip British Approved Name. It has also referred to as testosterone heptanoate.

Brand names Testosterone enanthate is marketed primarily under the brand name Delatestryl. It is or has been marketed under a variety of other brand names as well, including, among others:

Andro LA Andropository Depandro Durathate Everone Testostroval Testrin Testro LA Xyosted pharmaqo labs

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Testosterone enanthate

Start with the simplest possible case. Write down what Testosterone enanthate 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 Testosterone enanthate 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 Testosterone enanthate 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 Testosterone enanthate

In research: Testosterone enanthate 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 Testosterone enanthate 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: Testosterone enanthate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Androgens, Androstanes, Enanthate esters, so understanding it makes those chapters shorter.
In everyday life: Look for Testosterone enanthate 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 Testosterone enanthate in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Testosterone enanthate 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 Testosterone enanthate out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Testosterone enanthate in simple terms?

Testosterone enanthate is used in the treatment of low testosterone levels in men. It is also used in hormone therapy for transgender men.

Why does Testosterone enanthate 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 Testosterone enanthate?

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 Testosterone enanthate.