Can Immunotherapy Cause Low Libido and How Can Patients Cope?

Yes, low libido can occur during immunotherapy, often due to treatment‑related hormonal (endocrine) changes and the emotional and physical stress of cancer care. ^[1] Changes in mood, fatigue, and endocrine gland issues (thyroid, pituitary, adrenal) linked to immunotherapy can reduce sex drive. ^[1] Immunotherapy may cause thyroid dysfunction or hypophysitis (inflammation of the pituitary), which can lead to symptoms like extreme tiredness, weight changes, mood shifts, and decreased sex drive. ^{[2] [3]} Sexual interest can also decline simply because of the burden of treatment, body changes, and fatigue, even without a specific endocrine disorder. ^{[4] [5]} A decrease in sexual desire during or after cancer treatment is common and multifactorial. ^[6]

Why Libido Can Drop During Immunotherapy

• Endocrine side effects: Immune checkpoint inhibitors can inflame or disrupt glands like the thyroid and pituitary, leading to hypothyroidism or hypophysitis; both can cause low energy, mood changes, and reduced sex drive. ^{[2] [3]} Signs include persistent headaches, dizziness, severe fatigue, weight changes, feeling cold, hair loss, constipation, and decreased sex drive. ^[1]
• Central hormone deficiency: Pituitary inflammation (hypophysitis) can lower sex hormones (testosterone in men; estrogen in premenopausal women), contributing to low libido. ^[7]
• Cancer‑related stress and fatigue: Treatment side effects (pain, weakness, scars, drains), emotional strain, anxiety, and depression can lessen sexual interest and enjoyment. ^{[4] [5]}
• Chemotherapy overlap: If receiving chemotherapy with immunotherapy, fatigue and blood count issues can also affect sexual desire and activity choices. ^{[8] [9]}

Symptoms That Suggest Hormonal Causes

• Decreased sex drive with fatigue, mood changes, weight loss/gain, feeling cold, constipation, or hair thinning can point to thyroid or pituitary involvement. ^[1]
• New or persistent headaches, dizziness, confusion, or low blood pressure may be related to pituitary problems and warrant prompt evaluation. ^[10]

When to Seek Medical Evaluation

If libido remains low or is accompanied by fatigue, mood changes, headaches, or significant weight shifts, ask your care team to check endocrine labs. ^[7] Suggested tests during immunotherapy include morning cortisol and ACTH (for adrenal function), TSH and free T4 (thyroid), and if symptoms like loss of libido are present LH/FSH with testosterone (men) or estrogen/FSH (premenopausal women). ^[7] Early identification and treatment (for example, thyroid hormone replacement or managing hypophysitis) can improve energy and sexual interest. ^[10]

Practical Coping Strategies

• Talk openly with your clinician: It’s common and appropriate to discuss sexual health during cancer treatment; clinicians can suggest treatments and tips tailored to your situation. ^[11]
• Manage endocrine issues: Treating hypothyroidism or pituitary‑related hormone deficits can meaningfully improve libido and wellbeing. ^{[2] [3]}
• Address fatigue and mood: Fatigue management, counseling, and support for anxiety or depression can help restore interest in sex. ^[4]
• Adapt intimacy: Explore non‑intercourse intimacy, schedule sexual activity for times you have more energy, and use lubricants to ease discomfort if dryness is present. ^{[4] [5]}
• Partner communication: Sharing concerns and needs with a partner often reduces pressure and enhances connection, which can gradually improve desire. ^{[12] [13]}
• Specialist referral: Consider a sexual health clinic experienced in cancer survivorship for tailored strategies (e.g., pelvic floor therapy, vaginal moisturizers, erectile aids, or hormonal therapy when appropriate). ^{[14] [15]}

What to Ask Your Care Team

• “Could my low libido be related to thyroid or pituitary side effects from immunotherapy, and should we check hormones?” ^[7]
• “Which side effects of my treatment might affect sex, and how long could they last?” ^[16]
• “What treatments or medications can help, and where can I get more information?” ^{[16] [11]}

Key Takeaways

• Low libido during immunotherapy is not uncommon and can stem from both endocrine side effects and the overall stress of cancer treatment. ^{[1] [4]}
• Testing for endocrine causes (thyroid, pituitary/adrenal, sex hormones) is reasonable when libido drops with fatigue, mood changes, or headaches. ^{[7] [10]}
• Practical coping medical management, emotional support, communication, and adapting intimacy can meaningfully improve sexual wellbeing during treatment. ^{[4] [11]}