How do hormones work and what is the typical regimen for hormone replacement therapy?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Article Review Status
Submitted
Under Review
Approved

Last updated: May 31, 2025 • View editorial policy

From the Guidelines

Hormones work as chemical messengers in the body, and hormone replacement therapy (HRT) should be individualized based on symptoms, risks, and goals, with regular monitoring of hormone levels, side effects, and health parameters. Hormone replacement therapy typically involves estrogen for women who have undergone menopause, often combined with progesterone for those with an intact uterus.

  • A standard regimen includes oral estradiol (0.5-1mg daily), transdermal estradiol patches (0.025-0.1mg/day, changed twice weekly), or estradiol gel (0.5-1.5mg daily) 1.
  • Progesterone is usually given as micronized progesterone (100-200mg daily) or medroxyprogesterone acetate (2.5-5mg daily).
  • For transgender individuals, feminizing hormone therapy typically includes estradiol (2-6mg daily oral or 0.1-0.4mg/day transdermal) plus spironolactone (100-300mg daily) or another anti-androgen.
  • Masculinizing therapy involves testosterone (50-100mg weekly by injection, 50-100mg daily by gel, or 2.5-10mg daily by patch). The effectiveness of HRT stems from replacing hormones the body no longer produces adequately, helping restore physiological functions and alleviate symptoms associated with hormone deficiencies. The routine use of hormone replacement therapy is not currently recommended due to the associated risks of breast cancer, cardiovascular disease, and thromboembolic disease, but it may be considered in women who experience severe menopausal symptoms, and should be used only for a limited period of time and at the lowest effective doses 2. Treatment usually continues for several years for menopausal symptoms or indefinitely for transgender individuals, with dosages adjusted as needed. The quality of evidence on the benefits and harms of HRT varies for different hormone regimens, and until data indicate that other HRT regimens have a favorable balance of benefits to harms, a cautious approach would be to avoid using HRT routinely for the specific purpose of preventing chronic disease in women 3, 4, 5, 6.

From the FDA Drug Label

When estrogen is prescribed for a postmenopausal woman with a uterus, a progestin should also be initiated to reduce the risk of endometrial cancer. Use of estrogen, alone or in combination with a progestin, should be with the lowest effective dose and for the shortest duration consistent with treatment goals and risks for the individual woman.

The typical regimen for hormone replacement therapy involves using the lowest effective dose of estrogen, such as estradiol, and adjusting as necessary to control symptoms. The medication should be discontinued as promptly as possible, with attempts to discontinue or taper made at 3-month to 6-month intervals.

  • The usual initial dosage range is 1 to 2 mg daily of estradiol, adjusted as necessary to control presenting symptoms.
  • Administration should be cyclic (e.g., 3 weeks on and 1 week off). However, how hormones work is not directly addressed in the provided drug label 7.

From the Research

How Hormones Work

  • Hormones are chemical messengers that play a crucial role in various bodily functions, including growth, development, and metabolism 8, 9.
  • They are produced by endocrine glands and travel through the bloodstream to reach their target cells, where they bind to specific receptors and trigger a response 10, 11.
  • In the context of menopause, hormones such as estrogen and progesterone help regulate symptoms like hot flashes, mood changes, and vaginal dryness 8, 9.

Hormone Replacement Therapy (HRT) Regimen

  • HRT typically involves a combination of estrogen and progesterone, which can be administered orally, transdermally, or vaginally 10, 12.
  • The dosage and duration of HRT vary depending on the individual's symptoms, medical history, and lifestyle 8, 9.
  • Common HRT regimens include continuous daily oral micronized estradiol and progesterone, or cyclic conjugated estrogens and medroxyprogesterone acetate 10, 11.
  • Progesterone-only therapy has also been shown to be effective in managing menopausal symptoms, particularly vasomotor symptoms, in some studies 8, 9.

Types of Progestogens

  • Progestogens, such as micronized progesterone and synthetic progestins, are used in HRT to prevent endometrial hyperplasia and cancer 12.
  • Micronized progesterone, medroxyprogesterone acetate, and norethindrone acetate are the most commonly used progestogens in HRT 12.
  • Each progestogen has its own clinical properties and characteristics, and clinicians should be familiar with these differences to provide effective care for menopausal women 12.

Benefits and Risks of HRT

  • HRT has been shown to improve symptoms like hot flashes, night sweats, and vaginal dryness, as well as reduce the risk of osteoporosis and fractures 10, 11.
  • However, HRT also carries potential risks, such as increased risk of breast cancer, venous thromboembolism, and cardiovascular disease 9, 11.
  • The benefits and risks of HRT vary depending on the individual, and clinicians should carefully weigh these factors when determining the best course of treatment 11.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Review of menopausal hormone therapy with estradiol and progesterone versus other estrogens and progestins.

Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 2022

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.