HRT side effects in the first three months: what is normal and when to adjust

The body has to adjust to a new level of hormones, and individual sensitivity varies. Oestrogen can cause fluid shifts, breast fullness and headaches, while the progestogen can cause bloating, mood changes and breast tenderness in some. Symptoms resemble premenstrual symptoms because the same hormones are involved. The dose, route and type of progestogen all influence what you feel.

• Breast tenderness: often eases after a few weeks; a lower dose or a different progestogen can help.

• Bloating and fluid retention: may settle; changing the route or progestogen can help.

• Headaches: track timing; patches and gels give steadier levels than tablets for some people.

• Nausea: take oral products with food, or change the route.

• Skin irritation from patches: rotate sites and try another brand or a gel.

• Mood changes: may relate to the progestogen; discuss alternatives.

With a sequential regimen, a monthly bleed is expected. With a continuous combined regimen, irregular spotting or bleeding is common in the first three to six months and usually settles. Bleeding that is heavy, prolonged, starts after a period of no bleeding on a stable regimen or persists beyond the expected settling time should be assessed, since sometimes a scan or biopsy is needed to exclude other causes. Do not assume that all bleeding is a side effect.

Symptom relief may begin within weeks, but full benefit often takes up to three months. Making several changes at once makes it hard to see what is working. Unless side effects are troublesome, many clinicians suggest staying on one regimen for the first few months and keeping a symptom diary. If you cannot tolerate it, call your prescriber before stopping.

A prescriber can alter the dose, change the oestrogen route, switch the type of progestogen or change the regimen. Switching from oral to transdermal can reduce certain effects. Increasing the dose may be needed if symptoms are not controlled. Not every combination suits every person, and finding the right one can take time. Review is not a sign of failure.

Contact a clinician urgently for chest pain, breathlessness, a painful swollen leg, sudden severe headache, visual disturbance, weakness or numbness on one side, jaundice or severe abdominal pain. Call 999 if symptoms suggest stroke or pulmonary embolism. Report heavy bleeding or bleeding that does not settle.

Record your symptoms, dose, product, bleeding and any side effects. Take the record to your review. Note any other new medicines or supplements, which may interact. If you are unsure whether a symptom is related, include it anyway.