Continuous vs Sequential HRT: Which Regimen Is Right for Perimenopause?

Two Ways to Take HRT

When a doctor prescribes combined HRT (containing both estrogen and progesterone), they will recommend one of two regimens: sequential (also called cyclical) or continuous (also called continuous combined). The choice between them is not arbitrary. It depends primarily on where you are in the menopausal transition and whether you have had a period in the last year. Understanding the difference helps you have a more informed conversation with your doctor and reduces the surprise of unexpected bleeding, which is one of the most common reasons women discontinue HRT unnecessarily.

How Sequential HRT Works

In sequential HRT, estrogen is taken every day while progesterone is added for 12 to 14 days of each calendar month (similar to the natural luteal phase of the menstrual cycle). At the end of the progesterone phase, the withdrawal of the progestogen causes the uterine lining to shed, producing a withdrawal bleed. This is a predictable, lighter bleed that occurs monthly and is distinct from a natural period. Sequential HRT is designed for women who are still having periods, whether regular or irregular, which means it is typically the appropriate regimen during perimenopause itself. The monthly bleed is expected and planned for. Some women find it reassuring that their body is still cycling in a predictable way.

How Continuous Combined HRT Works

In continuous combined HRT, both estrogen and progesterone are taken every day without a break. Without the cyclical withdrawal of progesterone, the uterine lining does not build up and does not shed, so there is no withdrawal bleed. This is the appropriate regimen for women who are postmenopausal, defined as having had no natural period for at least 12 consecutive months. When started correctly in a postmenopausal woman, continuous HRT produces no bleeding within a few months. However, if started too early (before the 12-month period-free threshold), it often causes unpredictable, irregular spotting because the uterine lining has not fully stabilised. This irregular bleeding is not dangerous in itself but requires investigation to rule out endometrial abnormalities.

Why Timing Matters So Much

The most common mistake in HRT prescribing is starting a woman who is still in perimenopause on a continuous combined regimen. Because perimenopausal women still have some estrogen production and occasional ovulation, the uterine lining has not settled. Adding continuous progestogen to an unstable hormonal environment causes erratic bleeding that is uncomfortable and alarming. This is not a sign that something is medically wrong, but it does cause many women to stop HRT before it has had time to work. The corrective approach is straightforward: switch to a sequential regimen during perimenopause and transition to continuous combined after 12 months without a natural period.

Progesterone vs Progestogen: A Related Distinction

Within each regimen type, there is also a choice between body-identical progesterone (micronised progesterone, such as Utrogestan) and synthetic progestogens (like norethisterone or levonorgestrel). Body-identical progesterone is chemically identical to the progesterone your ovaries produce and has a more neutral side-effect profile, particularly for mood and sleep. Some women find synthetic progestogens worsen mood, cause bloating, or disrupt sleep. This is a separate but related conversation to discuss with your prescriber when choosing your regimen. Both types are available in sequential and continuous forms.

Bleeding Expectations with Each Regimen

With sequential HRT, a monthly withdrawal bleed is expected and normal. It is typically lighter and shorter than a natural period. Any bleeding that occurs outside the expected window, heavy bleeding, or irregular spotting should be reported to your doctor. With continuous combined HRT in a correctly postmenopausal woman, light spotting in the first three to six months of starting is common as the body adjusts. Persistent bleeding beyond six months or any significant bleeding after a period of none should be investigated. In neither case does bleeding automatically indicate a problem, but it always warrants medical review to be sure.

Making the Decision with Your Doctor