What Is HRT? A Simple Guide to Hormone Replacement Therapy

A plain-English guide to hormone replacement therapy — what it does, the forms it comes in, and what to expect when you start.

Part of the Complete Hormone Replacement Therapy Guide.

Hormone replacement therapy (HRT) is a prescription treatment that replaces the hormones — mainly oestrogen, and where needed progesterone — that your body stops producing during the menopause. It is the most effective treatment for menopausal symptoms such as hot flushes, night sweats, low mood, poor sleep and vaginal dryness, and it also protects your bones against osteoporosis.

This guide explains what HRT actually does, the forms it comes in, and what to expect when you start. For a full breakdown of benefits, risks and who HRT suits, see our complete Hormone Replacement Therapy guide.

What does HRT do?

During the menopause transition, the ovaries gradually stop producing oestrogen and progesterone. Oestrogen affects far more than fertility — it helps regulate body temperature, mood, sleep, bone density, vaginal and bladder tissue, and cardiovascular health. When levels fall, all of these systems are affected, which is why menopausal symptoms are so varied.

HRT restores oestrogen to physiological levels. In practice, that means it:

• Stabilises the brain's temperature control centre, reducing hot flushes and night sweats by around 75%
• Restores vaginal and urinary tract tissue health, easing dryness, discomfort during sex and recurrent UTIs
• Supports mood, concentration and sleep quality
• Slows bone loss, reducing fracture risk
• May support heart health when started under 60 or within 10 years of menopause

If you still have your uterus, oestrogen is combined with a progestogen. This protects the womb lining, which oestrogen alone would over-stimulate. Women who have had a hysterectomy take oestrogen only.

The main types of HRT

Combined HRT (oestrogen + progestogen)

For women with a uterus. It comes in two patterns: cyclical (progestogen for part of each month, producing a monthly bleed — used during perimenopause) and continuous (both hormones daily, no expected bleed — used once you're 12+ months past your last period).

Oestrogen-only HRT

For women who have had a hysterectomy. The simplest regimen, with a lower breast cancer risk than combined HRT.

Local (vaginal) oestrogen

Creams, pessaries or rings that treat vaginal and urinary symptoms directly, with minimal absorption into the bloodstream. Can be used alone or alongside systemic HRT. See our vaginal oestrogen guide.

Testosterone

Sometimes added for persistent low libido that hasn't responded to standard HRT. It is prescribed off-label in the UK. See our testosterone for menopause guide.

How is HRT taken?

Transdermal HRT (patches, gels, spray) is absorbed through the skin, bypassing the liver. NICE guidance notes it does not carry the small increase in blood-clot (VTE) risk associated with tablets, so it's often preferred — especially if you have clot risk factors or a higher BMI.

What is body-identical HRT?

Body-identical HRT uses hormones chemically identical to those your body makes — typically transdermal estradiol plus micronised progesterone (Utrogestan). It is regulated, widely prescribed and endorsed by the British Menopause Society, and is different from unregulated compounded "bioidentical" hormones. Read more in our body-identical HRT guide.

Is HRT safe? A brief summary

For most healthy women under 60 who start HRT within 10 years of menopause, NICE guideline NG23 (2015, updated November 2024) concludes the benefits outweigh the risks. The main considerations are a small increase in breast cancer risk with combined HRT after around five years of use, and a small clot risk with tablets (not skin-based HRT). Every prescription should follow an individual benefit-risk assessment. For the full evidence picture, see Is HRT safe? Facts and myths.

What to expect when starting

Most women notice hot flushes improving within 4 weeks, with full benefit by 3 months. Mild side effects — breast tenderness, bloating, irregular bleeding — are common early on and usually settle; see our HRT side effects guide. A review at 3 months checks your dose is right, then annually thereafter.

If you think HRT could help you, Access Doctor's pharmacist independent prescribers can assess you through a confidential online consultation and, where appropriate, prescribe the right regimen with discreet next-day delivery.