Ana Maria Kausel, MD, is a double board-certified endocrinologist affiliated with Mount Sinai St. Luke's/Mount Sinai West in New York City.

Testosterone enanthate is also known as testosterone heptanoate . It is an anabolic and androgenic steroid (AAS) drug used to treat low testosterone levels. Anabolic drugs work by building muscles, while androgenic means it enhances sex characteristics usually associated with males.

This drug has been used in medical procedures since the 1950s. It is known by a number of brand names, including Androfil, Depandro, Testrin, and Testro, and it is available by prescription only.

This article will explain how and why the drug is used. It also offers information about side effects and interactions with other drugs, and answers questions about related cancer risks from using it.

Testosterone enanthate is both a synthetic drug derived from the testosterone hormone and a testosterone pro-drug. This means it stimulates the body to make its own testosterone. It has strong androgenic effects and moderate anabolic effects.

The drug can be used for testosterone replacement therapy (TRT) in cisgender (cis) men with hypogonadism , or the decreased ability to make testosterone.

Causes of this condition include:

This drug can also be used for hormone therapy in transgender masculine people.

Other uses include treatment for delayed puberty in cis boys, and in metastatic breast cancer when it has spread in those who are postmenopausal.

The drug is also sometimes used controversially as an anti-aging therapy in older cis men. Testosterone levels in cis men can drop steeply after the age of 50, leading to a condition known as andropause.

This video has been medically reviewed by Rochelle Collins, DO.

Testosterone enanthate is a clear or yellowish fluid that comes in a 5-milliliter (ml) glass vial. It is injected into a buttock muscle every one to four weeks. To avoid large changes in hormone levels, and the mood swings that may come with them, lower doses are often used over shorter intervals.

The active drug, which is suspended in sesame oil, has a sustained release period of two to three weeks.

The dosage may vary by individual but it is typically used as follows:

While testosterone enanthate is sometimes used interchangeably with testosterone cypionate (depo testosterone), the latter is approved only for treating hypogonadism.

Testosterone enanthate is a steroid with both anabolic and androgenic properties. It is used to treat low testosterone levels or as hormone therapy in transgender people, among other uses. It is given by intramuscular injection in the buttocks.

This drug is designed to alter hormone levels, and it has benefits and risks. The side effects can range from mild to intolerable.

The most serious side effects are associated with testosterone abuse, an increasing problem in the United States. This led the Food and Drug Administration (FDA) to change the product warning label in 2016.

According to the FDA, the most common side effects associated with testosterone enanthate use include:

The severity of the side effects may improve for some people if the dose is reduced.

Less common, but potentially more serious side effects are associated with the long-term use or overuse of this drug. Some are related to its androgenic effects. Side effects can affect the heart and liver.

Call a healthcare professional if you have any of the following while using testosterone enanthate:

Some androgenic effects seen in those assigned female at birth, such as clitoral enlargement and a deepening voice, are permanent once they happen.

A low sperm count can reduce fertility in cis men.

The use of testosterone may increase the risk of some medical conditions, especially in cis men.

People who have severe untreated obstructive sleep apnea are at risk of sudden death when treated when testosterone.

Severe liver injury also may occur. Symptoms include fatigue, abdominal pain, nausea, vomiting, dark urine, and jaundice (yellowing of the eyes and skin).

Call 911 or seek emergency care if you have signs of a cardiovascular event, such as heart attack or stroke.

There are certain drugs that interact with testosterone enanthate. Some may need to be changed or adjusted while you are taking this medication.

The possible drug interactions include:

There are conditions in which this drug should not be used under any circumstances. This includes the use of testosterone in untreated prostate cancer or breast cancer, and in pregnancy.

The drug should also be avoided if you are allergic to sesame oil or any components of the drug.

TRT is known to improve urinary symptoms due to benign prostatic hyperplasia (BPH) in those assigned male at birth.

The prostate gland is an organ in those assigned male at birth. Its role is to secrete prostate fluid, one of the elements of semen. BPH, a common condition, limits the flow of urine, and may lead to bladder stones and reduced kidney function.

The same may not be true for those assigned male at birth who are diagnosed with a prostate malignancy. The link between testosterone use and prostate cancer remains highly controversial, and there have been reports that testosterone use in older men with untreated prostate cancer led to the cancer's spread. Other studies have not replicated this.

Despite the ongoing controversy, the FDA strongly advises against the use of testosterone in cis men with untreated prostate cancer.

Even for cis men without cancer, any elevation in the prostate-specific antigen (PSA) test within the first three to six months of starting testosterone would mean ending treatment until a complete cancer investigation can be done.

A 2006 study suggested an 11 percent increase in male breast cancer risk over a 10-year period of TRT use. The mechanism for this link is poorly understood and it hasn't been verified.

For cis men with untreated breast cancer, the FDA remains firm that use of testosterone poses a potential threat and should be avoided without exception. This is because of the conversion (aromatization) of testosterone into estradiol that happens naturally.

Testosterone enanthate should not be used in those who are pregnant. When given during pregnancy, testosterone can affect a female fetus. This condition causes physical characteristics typically associated with those assigned male at birth to be present in a fetus assigned female.

Some of the symptoms may be seen at birth, while others may only become apparent during puberty or later in life.

The risk of virilism, the medical term for this condition, in the baby is higher in pregnant women who themselves are experiencing virilism as a result of testosterone use.

Testosterone therapy must be stopped if a pregnancy is suspected. This is especially true during the first trimester. If the pregnancy is confirmed, the parents need to be advised about the potential hazards to the baby.

Testosterone use does not appear to pose any risk to a breastfeeding baby. The components of the drug are largely broken down before they reach the bloodstream, breast milk, or other body fluids. However, high levels of testosterone affect milk production, so breastfeeding might not be possible.

Testosterone use in cis men does not pose any risk to a pregnancy, either during conception or gestation.

Testosterone enanthate can offer potential benefits for cis men who have low testosterone levels. It also may be used to treat other conditions, including hormone therapy in transgender masculine people.

But it also carries with it many potential side effects and health risks. Some are quite serious, including the risk of heart attack and stroke in cis men. Drug interactions are a potential problem too, so it's important to tell your healthcare professional your complete health history if you are considering its use.

Whether you're thinking of TRT or considering testosterone enanthate for another reason, it's important to discuss all the possibilities with your healthcare provider. It's the best way to ensure that your decision to use the drug leads to a positive outcome.

Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life.

Thank you, {{form.email}}, for signing up.

There was an error. Please try again.

Endo Pharmaceuticals Solutions Inc. Delatestryl® (Testosterone Enanthate Injection, USP) [packaging label].

Unger CA. Hormone therapy for transgender patients. Transl Androl Urol. 2016;5(6):877-884. doi:10.21037/tau.2016.09.04

Giri D, Patil P, Blair J, et al. Testosterone therapy improves the first year height velocity in adolescent boys with constitutional delay of growth and puberty. Int J Endocrinol Metab. 2017;15(2): e42311. doi:10.5812/ijem.42311

Boni C, Pagano M, Panebianco M, et al. Therapeutic activity of testosterone in metastatic breast cancer. Anticancer Res. 2014;34(3):1287-90.

Pfizer. DEPO-TESTOSTERONE. Indications and Usage.

U.S. Food & Drug Administration. FDA approves new changes to testosterone labeling regarding the risks associated with abuse and dependence of testosterone and other anabolic androgenic steroids (AAS).

Michigan Medicine, University of Michigan. Testosterone injection.

Jarvis TR, Chughtai B, Kaplan SA. Testosterone and benign prostatic hyperplasia. Asian J Androl. 2015;17(2):212-6. doi:10.4103/1008-682X.140966

Michaud JE, Billups KL, Partin AW. Testosterone and prostate cancer: an evidence-based review of pathogenesis and oncologic risk. Ther Adv Urol. 2015;7(6):378-87. doi:10.1177/1756287215597633

Medras M, Filus A, Jozkow P, et al. Breast cancer and long-term hormonal treatment of male hypogonadism. Breast Cancer Res Treat. 2006;96(3):263-5. doi:10.1007/s10549-005-9074-y

Petering RC, Brooks NA. Testosterone therapy: Review of clinical applications. Am Fam Physician. 2017;96(7):441-449.

Thank you, {{form.email}}, for signing up.

There was an error. Please try again.