HRT side effects: what is common, what settles, what to report

The three-month rule, and why it matters

The great majority of side effects appear early and fade as the body adapts. Clinicians commonly suggest persisting for around three months before judging a preparation, unless something clearly needs attention sooner.

This is the most practically useful thing on the page, because a large share of people who stop hormone therapy do so in the first weeks, during the window when side effects are at their peak and about to decline.

The counterpart matters equally: side effects still present after three months are not something to endure indefinitely. They are information that the regimen needs changing.

Commonly reported, usually settling

Grouped by which component they are usually attributed to:

• Estrogen-related: breast tenderness and swelling, nausea, headaches, leg cramps, fluid retention
• Progestogen-related: bloating, mood changes or low mood, acne, breast tenderness, premenstrual-type symptoms in the progestogen phase
• Either: unscheduled bleeding or spotting, especially in the first three to six months
• Skin patches: local irritation or adhesion problems, which often resolve by rotating the site

What an adjustment can change

Side effects are frequently a problem of dose, type or route rather than of hormone therapy as a whole, and knowing the variables makes the conversation more productive:

Dose can be lowered, and starting lower and building up often avoids early effects entirely. Route can change: transdermal estrogen through skin bypasses the liver, which alters the side effect and risk profile compared with tablets, and nausea in particular often resolves with the switch.

The type of progestogen can change, which matters most for mood side effects, since different progestogens differ considerably in how they are tolerated. The pattern can change too — continuous rather than cyclical, or a hormonal intrauterine system delivering the progestogen locally.

What to report rather than wait out

These need contacting a clinician promptly rather than persisting through:

• Pain, swelling, redness or warmth in one calf, or sudden breathlessness or chest pain, which could indicate a clot
• A severe or unusual headache, particularly with visual disturbance, weakness or difficulty speaking
• Heavy or persistent bleeding, bleeding that begins after six months of settled treatment, or any change in an established bleeding pattern
• A new breast lump or nipple change
• Yellowing of the skin or eyes, or severe abdominal pain
• Marked low mood or worsening depression after starting

Separating side effects from risks

These are different conversations that constantly get merged. Side effects are the short-term, mostly transient effects described above. Risks — the discussion around breast cancer, clots and stroke — depend on your age, time since menopause, the type and route used, and your personal history.

That risk conversation cannot be had usefully on a web page, and should not be. It is individual, and it is the reason the decision belongs with a clinician who knows your history.

When to see someone

Book a review at around three months after starting, and do not treat early side effects as a verdict before then unless something on the list above applies.

If you have stopped hormone therapy because of side effects, it is worth knowing that a different dose, route or progestogen may be tolerated entirely differently. Many people conclude it does not suit them after trying only one preparation.