What is Testosterone Enanthate?

Testosterone enanthate used

Testosterone is a naturally occurring sex hormone produced in a man’s testicles. Small amounts of testosterone are also produced in a woman’s ovaries and adrenal system.
Testosterone Enanthate is used in men and boys to treat conditions caused by a lack of this hormone, such as delayed puberty, impotence, or other hormonal imbalances. This medicine is not for use in treating low testosterone without certain medical conditions or due to getting older.
Testosterone enanthate is used in women to treat breast cancer that has spread to other parts of the body (metastatic) and cannot be treated with surgery.
Testosterone will not enhance athletic performance and should not be used for that purpose.
Testosterone Enanthate may also be used for purposes not listed in this medication guide.
Testosterone is a sex hormone primarily found in males and functions to trigger the development of both primary and secondary sexual characteristics that occur during puberty. It is also found in females to a lesser amount and serves several important roles in the female physiological system.

The effects of testosterone typically begin to manifest in the first few weeks of intra-uterine life. At about the seventh week of gestation within the uterus, the presence of the Y chromosome leads to the development of the primordial testes. Once developed, the primordial testes begin to produce testosterone and Mullerian Inhibiting Factor, which are essential for the differentiation of the fetus into a male rather than a female. The release of testosterone in the uterus leads to the development of the male primary physical characteristics such as epididymis, vas deferens, seminal vesicles, penis, prostate gland, and the descent of the testicles into the scrotum in the last months of fetal life.

During puberty in males, there is a significant surge in testosterone produced and released within the body. This increase in testosterone production is under the control of the hypothalamic-pituitary-gonadal axis. The hypothalamus releases Gonadotropin-releasing hormone (GnRH) in the brain, which then travels down to the anterior pituitary gland by means of the hypothalamic-hypophyseal portal system. In the anterior pituitary gland, GnRH causes the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH). The released LH acts on the Leydig cells within the testes to increase the amount of testosterone produced. Once released, testosterone facilitates the development of secondary sexual characteristics in males, such as enlarged genitalia, increased libido, sperm production, deepening of the voice, and growth of male hair patterns on the body. 
In addition to the development of male secondary sexual characteristics, testosterone also serves other essential functions within the body. Some of these functions include: 

  • Skeletal muscle: Testosterone has a hypertrophic and hyperplastic effect on the muscle fibers within the skeletal muscular system. There is a significant increase in muscle growth during puberty due to the hypertrophic effects of testosterone. In men experiencing muscle loss due to aging, testosterone administration has been shown to aid in reversing this condition.
  • Bone: Testosterone has a significant impact on the development and maintenance of bone growth. It is converted to estradiol by means of the enzyme aromatase; estradiol minimizes the breakdown of bone by inhibiting the resorption of bone by osteoclasts. Additionally, testosterone is converted into dihydrotestosterone (DHT) by the enzyme 5-alpha reductase; DHT stimulates bone osteoblasts and the laying down of bone.
  • Blood: Testosterone stimulates the production of red blood cells in males. This is one of the reasons that males generally tend to have higher red blood cell levels compared to females. The process by which testosterone stimulates red blood cell production is not yet fully understood and is undergoing research.
  • Brain: Some studies have shown that testosterone levels in the body have an impact on the ability of males to reason and perform other higher mental functions. These studies indicate that most men suffering from hypogonadism due to low testosterone may experience some degree of memory impairment as well as impaired verbal and visual performance.
  • Mood: Though also poorly understood, testosterone levels in the body have been shown to have an effect on the mood and behaviors in males. There is an association between hypogonadism in men and depressive moods. Research performed revealed an improvement in moods in men with hypogonadism after treatment with testosterone supplements.
    Testosterone enanthate is an injectable testosterone supplement that is usually administered to treat low testosterone and other symptoms of hypogonadism in males. It is a slow-release oil-based ester that can be administered either intramuscularly or subcutaneously, depending on the health care provider’s preference or the individual receiving the injection. It was first used clinically as a treatment of low testosterone in 1937, and its use by men has since then significantly increased in popularity.


You should not be treated with testosterone if you have prostate cancer, male breast cancer, a serious heart condition, severe liver or kidney disease, or an allergy to castor oil or sesame oil. Testosterone Enanthate is not for use in treating low testosterone without certain medical conditions or due to getting older. Testosterone should not be used to enhance athletic performance.
Testosterone Enanthate is not for use in women who are pregnant.
Testosterone can increase your risk of heart attack, stroke, or death. You may need to stop using testosterone or start taking blood pressure medication.
Misuse of testosterone can cause dangerous or irreversible effects. Do not share this medicine with another person.
Before taking this medicine
You should not be treated with this medicine if you are allergic to testosterone, or if you have:

  • male breast cancer;
  • prostate cancer;
  • serious heart problems;
  • severe liver disease;
  • severe kidney disease; or
  • an allergy to castor oil or sesame oil.
    Testosterone Enanthate is not for use in women who are pregnant. This medicine can harm an unborn baby.
    Tell your doctor if you have ever had:
  • high blood pressure;
  • heart problems, coronary artery disease (clogged arteries);
  • a heart attack or stroke;
  • sleep apnea;
  • an enlarged prostate and urination problems;
  • high cholesterol or triglycerides;
  • cancer;
  • depression, anxiety, a mood disorder, suicidal thoughts or actions;
  • diabetes;
  • high red blood cell (RBC) counts; or
  • liver or kidney disease.
    Using testosterone may increase your risk of developing prostate cancer, liver problems, or heart problems (including heart attack, stroke, or death). Ask your doctor about these risks.
    Women using testosterone should not breastfeed.
    Testosterone should not be given to a child younger than 12 years old. Some types of this medicine are not approved for use by anyone younger than 18 years old.


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:

  • Male hypogonadism: 50 to 400 milligrams (mg) every two to four weeks
  • Delayed male puberty: 5 to 200 mg every two to four weeks, for four to six months
  • Metastatic breast cancer: 200 to 400 mg every two to four weeks
  • Transgender hormone therapy: 50 to 200 mg per week or 100 to 200 mg every two weeks
    How is Testosterone Enanthate given?
    Testosterone is injected under the skin or into a muscle, usually given every 2 to 4 weeks. Testosterone Enanthates should be given only by a healthcare professional.
    The length of treatment with Testosterone Enanthate will depend on the condition being treated.
    Testosterone can raise your blood pressure, which could increase your risk of heart attack, stroke, or death. Your blood pressure will need to be checked often. You may need to stop using testosterone or start taking blood pressure medication.
    You will need frequent blood tests.
    Testosterone can affect bone growth in boys who are treated for delayed puberty. Bone development may need to be checked with x-rays every 6 months during treatment.
    Testosterone Enanthate can affect the results of certain medical tests. Tell any doctor who treats you that you are using testosterone.
    Misuse of testosterone can cause dangerous or irreversible effects, such as enlarged breasts, small testicles, infertility, high blood pressure, heart attack, stroke, liver disease, bone growth problems, addiction, and mental effects such as aggression and violence. Stealing, selling, or giving away this medicine is against the law.
    If you have used too much testosterone, stopping the medicine may caused unpleasant withdrawal symptoms, such as depression, tiredness, irritability, loss of appetite, sleep problems, or decreased libido.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your Testosterone Enanthate.

What happens if I overdose?

Since Testosterone Enanthate is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid while receiving Testosterone Enanthate?

Follow your doctor’s instructions about any restrictions on food, beverages, or activity.

Testosterone Enanthate side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Tell your caregivers right away if you have a tight feeling in your throat, a sudden urge to cough, or if you feel light-headed or short of breath during or shortly after receiving the injection.
You will be watched closely for at least 30 minutes to make sure you do not have a reaction to the injection.
Call your doctor at once if you have:

  • chest pain or pressure, pain spreading to your jaw or shoulder;
  • shortness of breath, breathing problems at night (sleep apnea);
  • swelling in your ankles or feet, rapid weight gain;
  • a seizure;
  • unusual changes in mood or behavior;
  • increased or ongoing erection of the penis, ejaculation problems, decreased amounts of semen, decrease in testicle size;
  • painful or difficult urination, increased urination at night, loss of bladder control;
  • high levels of calcium in the blood–stomach pain, constipation, increased thirst or urination, muscle pain or weakness, joint pain, confusion, and feeling tired or restless; or
  • high potassium level–nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement;
  • liver problems–right-sided upper stomach pain, vomiting, loss of appetite, dark urine, jaundice (yellowing of the skin or eyes).
  • signs of a blood clot deep in the body–swelling, warmth, or redness in an arm or leg;
  • signs of a blood clot in the lung–chest pain, sudden cough, wheezing, rapid breathing, coughing up blood; or
  • signs of a stroke–sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, balance problems.
    Call your doctor at once if you notice any of these signs of excess testosterone:
  • acne;
  • changes in your menstrual periods (including missed periods);
  • male-pattern hair growth (such as on the chin or chest);
  • hoarse or deepened voice; or
  • enlarged clitoris.
    Your Testosterone Enanthates may be delayed or permanently discontinued if you have certain side effects.
    Common side effects (in men or women) may include:
  • breast swelling;
  • acne, increased facial or body hair growth, male-pattern baldness;
  • increased or decreased interest in sex;
  • headache, anxiety, depressed mood;
  • increased blood pressure;
  • numbness or tingly feeling;
  • abnormal liver function tests;
  • high red blood cell counts (hematocrit or hemoglobin);
  • increased PSA (prostate-specific antigen); or
  • pain, bruising, bleeding, redness, or a hard lump where the medicine was injected.

Side Effects

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.

Common Side Effects

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

  • Injection site pain and swelling
  • Headaches
  • Dizziness
  • Mood changes, including aggression
  • Depression or anxiety
  • Increased or decreased sex drive
  • Generalized tingling
  • Oily skin and acne
  • Thinning hair
  • Weight gain
    The severity of the side effects may improve for some people if the dose is reduced.

What other drugs will affect Testosterone Enanthate?

Tell your doctor about all your other medicines, especially:

  • insulin or oral diabetes medicine;
  • medicine to treat pain, cough, or cold symptoms;
  • a blood thinner-warfarin, Coumadin, Jantoven; or
  • steroid medicine-prednisone, dexamethasone, and others.
    This list is not complete. Other drugs may affect testosterone, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.


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.