HRT Blood Test Kit

Oestradiol (also spelled estradiol, abbreviated E2) is the most potent and biologically active form of oestrogen. Before menopause, it's produced primarily by the ovaries and plays essential roles in the menstrual cycle, bone health, cardiovascular protection, brain function, skin health, and vaginal/urinary tract maintenance. Oestradiol levels fluctuate throughout the menstrual cycle, peaking just before ovulation, and decline significantly during perimenopause and menopause as ovarian function wanes.

Low oestradiol levels are responsible for most menopausal symptoms: hot flushes, night sweats, sleep disturbances, mood changes, vaginal dryness and discomfort, reduced libido, and brain fog. Long-term oestrogen deficiency also increases the risk of osteoporosis (bone thinning) and may affect cardiovascular health. The goal of oestrogen replacement in HRT is to restore oestradiol to levels that relieve symptoms and protect bone health without being excessively high.

When monitoring HRT, oestradiol levels help assess whether you're achieving adequate replacement. While there's no single "optimal" level (treatment is guided primarily by symptoms), many specialists aim for oestradiol levels in the range of 200-600 pmol/L for symptom relief and bone protection, though this varies by individual and HRT type. Levels that are persistently low despite HRT may indicate a need for dose adjustment or a different delivery method. If you're using transdermal oestrogen (gels, patches, sprays), sample contamination can cause falsely elevated readings—always wear gloves when applying and avoid using fingers that have touched the product. Results should be discussed with your HRT prescriber who can interpret them in the context of your symptoms and treatment goals.

Progesterone is a steroid hormone produced by the corpus luteum (the remnant of the ovarian follicle after ovulation) during the second half of the menstrual cycle, and by the placenta during pregnancy. It prepares and maintains the uterine lining (endometrium) for potential pregnancy. After menopause, when ovulation no longer occurs, progesterone production drops to very low levels.

In HRT, progesterone (or a synthetic progestogen) is an essential component for any woman who still has her uterus. Oestrogen alone causes the endometrial lining to thicken continuously, which over time significantly increases the risk of endometrial hyperplasia and endometrial cancer. Progesterone opposes this effect, causing regular shedding (in cyclical regimens) or keeping the lining thin (in continuous combined regimens), thereby protecting against endometrial cancer. Women who have had a hysterectomy do not need progesterone with their HRT.

When monitoring HRT, progesterone levels help confirm that adequate endometrial protection is being achieved. The interpretation depends on your HRT regimen—cyclical (where progesterone is taken for part of the month) or continuous combined (where progesterone is taken every day). For those on micronised progesterone (body-identical progesterone such as Utrogestan), blood levels can be measured to confirm absorption and adequate dosing. Synthetic progestogens may not be accurately reflected in a progesterone blood test. Note on your request form what type of progesterone/progestogen you're taking and when you last took it. Results should be discussed with your HRT prescriber.

Follicle Stimulating Hormone (FSH) is produced by the pituitary gland in the brain and plays a crucial role in the reproductive system. In women, FSH stimulates the growth and development of ovarian follicles, each of which contains an egg. FSH levels vary throughout the menstrual cycle, rising in the first half to stimulate follicle development and then dropping after ovulation.

As women approach and enter menopause, FSH levels rise progressively. This occurs because the ovaries become less responsive to FSH stimulation, so the pituitary gland produces more FSH in an attempt to stimulate the ovaries—a classic negative feedback loop. Persistently elevated FSH (typically above 25-40 IU/L) combined with low oestradiol and absent periods is consistent with menopause. During perimenopause, FSH levels fluctuate considerably and may not always be elevated.

When taking HRT, FSH levels can provide useful information but require careful interpretation. Oestrogen replacement typically causes FSH to fall (as the pituitary senses adequate oestrogen and reduces its stimulation signal), though it may not return to premenopausal levels. A persistently very high FSH despite HRT could suggest inadequate oestrogen replacement, though the clinical picture (symptoms) is more important than targeting a specific FSH number. FSH is most useful as part of the overall picture alongside oestradiol levels and your symptom response. Results should be discussed with your HRT prescriber who can interpret them in the context of your individual situation.