How to start HRT: the practical first 90 days

Starting HRT is less dramatic than the marketing on either side suggests. It's not an instant transformation, and it's rarely a disaster. The first 90 days are the most informative — they settle the question of whether the regimen works for you and what tweaks make sense.

Choosing your starting regimen

Most women start on transdermal estradiol (patch or gel) plus oral micronized progesterone at bedtime if they have a uterus. Standard starting doses: 0.05 mg/day patch (changed twice weekly or weekly depending on brand) or 0.5–1.5 g/day gel; 100–200 mg progesterone nightly. Vaginal estrogen for genitourinary symptoms can be added or started alone (low-dose tablets, ring, or cream). Oral estradiol (1 mg) is a reasonable alternative when transdermal isn't practical, though it has slightly different metabolic effects.

Weeks 1–2: what to expect

Most women feel little in the first 7–10 days. Some report a mild "settling" or improved sleep within the first few nights, particularly with bedtime progesterone (it has mild sedative effects). Common early side effects: breast tenderness, slight bloating, mild headache, mood lability. These typically resolve within 2–4 weeks as your body acclimates.

Weeks 3–8: vasomotor symptom relief

Hot flashes and night sweats typically begin improving by week 2–3 and reach substantial improvement by week 6–8. If you're not seeing meaningful change at 8 weeks, dose may need to increase or form may need to change (skin absorption varies meaningfully person-to-person, particularly with gels). A 50–75% reduction in hot flash frequency is a typical good response.

Weeks 4–12: sleep, mood, cognition

Mood, sleep, and cognitive symptoms typically improve more slowly than vasomotor symptoms — partly because they involve more neural adaptation. Expect partial improvement by 4–6 weeks and stabilization by 12 weeks. If perimenopausal mood symptoms haven't improved by 3 months, consider whether the underlying diagnosis is actually major depression or PMDD (different treatment).

Common first-90-days events

Spotting or breakthrough bleeding is common with continuous combined regimens in the first 3–6 months — usually resolves on its own. Persistent bleeding beyond 6 months warrants endometrial assessment. Breast tenderness usually resolves by week 4; if persistent, the dose may be too high. Mood swings can briefly worsen before improving as your hormone milieu shifts. Skin reactions at patch sites — try rotating sites or switching to a different brand.

When to adjust

Plan a check-in at 3 months. Bring: a brief symptom diary (frequency and severity of hot flashes, sleep quality, mood, libido), any side effects, any bleeding pattern. Most women adjust dose at least once in the first 6 months — this is normal, not a sign something is wrong. Lower dose if side effects predominate; raise if symptom relief is partial.

When to call your clinician

Call between visits for: heavy or persistent vaginal bleeding (more than light spotting); calf swelling or chest pain (rule out VTE); sudden severe headache or vision changes; new breast lump; severe mood deterioration or suicidal ideation. None of these are common but all are worth same-day evaluation.

Setting expectations

HRT works well for vasomotor symptoms, sleep, mood lability, and genitourinary symptoms. It does not "reverse aging," restore reproductive function, or guarantee weight loss. Expectations matter: women who start HRT to feel "20 years younger" are often disappointed; women who start to relieve a specific symptom and accept dose-tuning over a few months are usually satisfied.

Informational only — your clinician will tailor the regimen and follow-up to your situation.