Dose of Progestogens in HRT – What is adequate dose?

Women with a uterus are required to take 2 hormones in their HRT- estrogen and progestogen. Progestogen protects the womb from cancer which occurs if estrogen is taken on its own.

British Menopause Society recommends dose of progestogen in HRT should be in proportion to dose of estrogen to prevent uterine cancer and unscheduled bleeding . If dose of estrogen is increased dose of progestogen should increase proportionately.  There is lack of safety evidence on adequate doses of progestogens when doses of estrogen taken are above licensed doses.

Studies have shown that hormone coil such as Mirena / Benilexa has 52 mg of progestogen hormone called Levonorgestrel which provides good protection from cancer of womb for upto 5 years in women taking high doses of Estrogen ( up to 100 mcg patches or 4 pumps of gel) but there is lack of evidence on higher doses than this.

The table below outlines the different strengths of estrogen doses and corresponding progestogen dose that provides protection from cancer of the womb for different strengths of licensed estrogen doses . High doses of estrogen are required mainly in younger women who have an early menopause under 40 and in early 40s or those who do not have relief on standard doses.