Women’s Health and Hormonal Medicine Side Effects

Hormonal medicines are used across contraception, heavy or painful periods, endometriosis, fertility treatment, polycystic ovary syndrome and menopause. They act on systems that affect bleeding, mood, skin, weight and sexual function, which is why their side effects reach into so many areas of daily life at once.

Two things are worth saying plainly. Most hormonal side effects settle within the first three months, so judging a method too early is common. And effects that persist beyond that are worth changing method over, rather than accepting. Women’s reports of mood and libido effects in particular have historically been under-recognised, and there is no reason to tolerate something that is affecting your life.

Common hormonal medicine side effects

Irregular bleeding or spotting, most common in the first months
Breast tenderness
Headaches
Nausea
Mood changes
Bloating or fluid retention
Skin changes, in either direction
Changes in sexual desire

Bleeding, mood, skin, weight and cycle changes

Bleeding is the most common reason people stop a method, and the pattern differs by type. Combined pills usually settle into a predictable cycle. Progestogen-only methods are unpredictable: an intrauterine system typically causes irregular bleeding for three to six months and then lighter or absent periods, while an implant’s early pattern tends to persist. See irregular bleeding on hormonal medicine.

Mood. Low mood, anxiety or irritability are reported often enough to be taken seriously, and are a legitimate reason to change method. See hormonal contraception and mood.

Libido. Reduced desire is commonly reported and rarely raised. It is worth mentioning. See medicines and low libido.

Weight. Evidence for substantial weight gain is stronger for injectable contraception than for most other methods, though fluid retention can make anything feel that way early on. See birth control and weight gain.

Skin. Some methods improve acne over months; others can worsen it. See hormonal contraception and acne.

Serious warning signs that need medical attention

Get emergency help for signs of a clot or stroke, which matter most with oestrogen-containing methods:

Pain, swelling, warmth or redness in one calf or thigh
Sudden breathlessness, chest pain worse on breathing in, or coughing up blood
Sudden severe headache unlike any you have had before
Weakness or numbness on one side, difficulty speaking, or sudden loss of vision
Severe abdominal pain, or yellowing of the eyes or skin

See hormonal medicine and blood clot symptoms.

Contact a doctor promptly for very heavy or prolonged bleeding, severe pelvic pain, a new breast lump, severe or persistent low mood, or a missed period with abdominal pain.

Who may be at higher risk?

Tell your clinician about migraine with aura, smoking particularly over 35, a personal or family history of blood clots, high blood pressure, a history of breast cancer, liver conditions, or unexplained vaginal bleeding not yet investigated. Several of these steer you away from oestrogen-containing methods towards progestogen-only ones, which is a change of method rather than having no options.

St John’s Wort and some epilepsy medicines reduce contraceptive effectiveness. See supplements that affect birth control.

What to discuss with your doctor, pharmacist or clinic

How long should I give this before judging it?
What bleeding pattern should I expect, and when should it settle?
If mood or libido is affected, what are the alternatives?
Given my history, are oestrogen-containing methods suitable?
What symptoms mean I should seek urgent help?

Related contraception, HRT and hormonal medicine guides

Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.