Androgens are male sex hormones responsible for the development of male reproductive tissues, secondary sexual characteristics, and overall masculine physiology. The primary androgen is testosterone, which plays a major role in fertility, muscle development, bone density, and red blood cell production.
In medicine, testosterone is prescribed for hypogonadism, delayed puberty, certain cancers, and muscle-wasting disorders. However, its misuse—for athletic enhancement or bodybuilding—poses serious health risks. This guide breaks down everything students need to know.
What Are Androgens?
Androgens are steroid hormones produced primarily in the testes in males and in smaller amounts in the ovaries and adrenal glands in females.
The principal androgen used in therapy is testosterone, which is available in multiple formulations:
- Oral
- Intramuscular (IM)
- Subcutaneous (SQ)
- Topical gels
- Transdermal patches
These forms allow flexibility depending on patient needs and medical conditions.
Classification
Pharmacologic Class (P): Androgens
Therapeutic Class (T): Androgens
These drugs are classified as controlled substances in many countries due to high misuse potential.
Uses of Testosterone (Androgens)
Testosterone is prescribed for several important clinical conditions:
Hypogonadism
To replace testosterone in males with low hormone levels.
Delayed Puberty in Males
Helps induce development of sexual characteristics.
Testicular Failure
Used when the testes cannot produce adequate testosterone.
Postmenopausal Breast Cancer
Testosterone may help suppress estrogen effects in certain cancer types.
Additional Uses
- Muscle wasting associated with chronic illness
- Low libido related to testosterone deficiency
- Gender-affirming hormone therapy for transgender men (under specialist supervision)
Mechanism of Action (MOA)
Testosterone enters cells and binds to androgen receptors, forming a hormone–receptor complex. This complex interacts with specific DNA sequences to:
- Promote development of male sexual traits
- Increase skeletal muscle mass
- Stimulate sperm production
- Increase red blood cell formation
- Influence mood and energy levels
These effects explain both the therapeutic benefits and many of the risks associated with testosterone therapy.
Adverse Effects of Androgens (Testosterone)
Testosterone has a well-known risk profile. A helpful mnemonic from your visual is MUSCLE.
M – Misuse Potential
Athletes may misuse testosterone for performance enhancement.
U – Unusual Swelling (Edema)
Fluid retention is common.
S – Suppressed Clotting Factors
Increased risk of bleeding disorders.
C – Cholestatic Hepatitis
Liver toxicity is a major concern with oral testosterone.
L – Low Mood (Sadness)
Mood swings, irritability, or depression may occur.
E – Electrolyte Imbalances
Testosterone may increase or decrease levels of:
- Chloride (Cl)
- Calcium (Ca)
- Sodium (Na)
- Potassium (K)
- Phosphate (Ph)
- Blood glucose (BG decreases → hypoglycemia risk)
Additional Side Effects
- Acne, oily skin
- Male-pattern baldness
- Increased libido
- Gynecomastia (due to conversion to estrogen)
- Aggressive behavior
- Testicular atrophy with chronic use
- Infertility (suppression of natural testosterone production)
Drug Interactions
Cyclosporine
Increases risk of hepatotoxic (liver-damaging) effects.
Insulin
Testosterone enhances the action of insulin, increasing risk of hypoglycemia.
Other Interactions
- Anticoagulants: altered clotting
- Corticosteroids: worsened edema
- Hepatotoxic drugs: higher liver injury risk
Close monitoring is necessary when combining testosterone with interacting medications.
Contraindications
Testosterone therapy should be avoided in:
Pregnancy (Category X)Causes virilization of female fetus.
Testosterone stimulates cancer growth.
Hormone-dependent cancer worsens with androgens.
Testosterone increases calcium levels.
Careful patient evaluation is essential before prescribing testosterone.
Black Box Warning
Testosterone carries serious risks:
- Increased risk of stroke
- Increased risk of myocardial infarction (MI)
- Risk of cardiovascular death
Misuse or high doses greatly increase these dangers.
Clinical Pearls for Students
- Testosterone is not recommended for normal aging or athletic enhancement.
- Topical testosterone can transfer to others—avoid skin contact.
- Excessive testosterone suppresses LH and FSH, reducing fertility.
- Testosterone can worsen sleep apnea.
- Liver damage is more common with oral testosterone than injectable forms.
These points often appear in pharmacology exams and NCLEX-style questions.
Patient Education
Patients must be advised to:
- Apply topical testosterone only as directed and wash hands afterward
- Rotate injection or patch sites
- Report symptoms of liver injury (jaundice, dark urine)
- Monitor for swelling, weight gain, or breathing difficulty
- Check blood glucose regularly (for diabetic patients)
- Avoid misuse for sports or muscle enhancement
Education ensures safe use and reduces risk of complications.
Androgens like testosterone are powerful hormones essential for male sexual development, muscle growth, bone density, and fertility. In clinical medicine, testosterone replacement offers significant benefits to patients with deficiency or certain cancers. However, testosterone therapy carries major risks including liver toxicity, cardiovascular events, mood changes, and misuse potential.
A strong understanding of testosterone’s mechanism, uses, interactions, and black box warnings is crucial for healthcare students preparing for exams or clinical practice.
FAQs on Androgens (Testosterone)
1. Why is testosterone a controlled substance?
Because it has high potential for misuse in sports and bodybuilding.
2. Does testosterone improve athletic performance?
Yes, but misuse is illegal and dangerous due to severe health risks.
3. Can testosterone cause infertility?
Yes. High doses suppress sperm production.
4. Is testosterone safe for women?
Only in specific medical conditions and under specialist supervision, such as certain types of breast cancer.
5. What is the safest way to take testosterone?
Transdermal and injectable forms have fewer liver risks compared to oral formulations.
6. Can testosterone cause mood changes?
Yes, including aggression, irritability, and depression.
7. Is testosterone therapy lifelong?
It depends on the underlying condition—some cases require lifelong therapy, others do not.
