is hrt good or bad

HRT is neither good nor bad — it depends on the formulation, the route, your age at start, and your uterus.

The two biggest randomized trials on this question are the Women’s Health Initiative and a smaller Danish study. They point in opposite directions. The WHI found that women who started combination estrogen‑plus‑progestin after age 60 had more heart attacks, strokes, and breast cancers [1, 6]. The Danish DOPS trial, which started women earlier (average age 50 instead of 63), found half as many heart attacks and deaths in the treated group [4, 7]. The difference is almost certainly timing — starting near menopause looks protective for the heart; starting a decade later looks harmful.

Breast cancer risk is the clearest split. In the WHI, combination therapy raised breast cancer incidence by about 25% (HR 1.25) and breast cancer death by about 96% (HR 1.96) [1]. Estrogen alone, in women without a uterus, lowered breast cancer incidence (HR 0.71) and death (HR 0.37) [1]. A large 2024 Norwegian study confirms that current estrogen‑progestin users had a 44% higher incidence of breast cancer and a 61% higher breast‑cancer mortality, with risk increasing by about 4% per year of use [2]. The French MISSION study found no overall increase, but it was small and short — only about 8 years of average exposure [3].

Route matters. Oral estrogen goes through the liver and raises clotting factors. Transdermal (patch, gel) does not. Observational data consistently shows transdermal estradiol carries a lower risk of venous thromboembolism (VTE) and stroke, especially in women who already have risk factors [5, 9]. The ESTHER study reported an odds ratio for VTE of about 10 with oral estrogen but only about 3 with transdermal [9].

The table below shows the key tradeoffs across different regimens, using numbers from the largest trials:

The bottom line for the reader: HRT is a serious medical intervention with real benefits for hot flashes, bone density, and possibly heart disease if started early, and real harms including breast cancer (with combination therapy), clots (with oral therapy), and stroke. If you have a uterus, you need progestin with estrogen, which raises breast cancer risk. If you do not, estrogen alone may lower it. Transdermal routes are safer than oral for clotting. No one should stay on it longer than needed — every extra year adds risk. The evidence does not support long-term use for disease prevention.

My call: HRT can be reasonable for symptom relief in early menopause, but it requires choosing the lowest effective dose, the safest route (transdermal), and the shortest duration. The benefit‑harm balance shifts sharply against it with age, with combination therapy, and with oral estrogen. Confidence: moderate — the WHI and DOPS results are solid, but the evidence remains conflicted on timing, formulation, and who benefits most.