Perimenopause / Menopause: When Should You Have a Blood Test?

Perimenopause (or premenopause) refers to the transition phase before a woman reaches menopause. It generally begins between the ages of 40 and 50 and can last from a few months to several years, on average 4 years, sometimes up to 10. (1) During this perimenopause transition, oestrogen and progesterone production fluctuates and then gradually declines, leading to the appearance of the first clinical signs.

Menopause is officially reached when periods have been absent for 12 consecutive months: at this stage, the hormonal decline is definitive and the ovaries almost completely cease to function. (2) These changes are not insignificant for the body, and each patient experiences them in her own way. Some women go through a genuine upheaval, while others navigate this period more quietly.

The average age of entry into perimenopause is generally around 45, with confirmed menopause around the age of 50-52 in France (3). However, these figures remain indicative: some women reach menopause as early as 40, others after 55. This is why an assessment tailored to your age, your cycle, and your symptoms can be very worthwhile.

The most frequently reported symptoms in patients include (3):

• Hot flushes and night sweats
• Sleep disturbances and persistent fatigue
• Mood swings, anxiety, irritability
• Brain fog, difficulty concentrating
• Irregular menstrual cycles, ovulation disorders, heavier or less frequent periods
• Vaginal dryness, decreased libido
• Unexplained weight gain, changes in fat distribution
• Joint pain, loss of muscle tone

These symptoms can vary enormously from one woman to another: some patients barely notice them, while others find their quality of life significantly affected. In all cases, understanding what is happening in your body is always a good idea and is the first step towards appropriate care.

Beyond day-to-day comfort, the decline in oestrogen has longer-term consequences for health. Several clinical studies show that perimenopause marks a turning point for three key areas of women's health, which it is valuable to anticipate.

Cardiovascular health

Before the menopause, oestrogen has a protective effect on the cardiovascular system. As levels decline, women's cardiovascular risk gradually increases, eventually reaching that of men (4). Lipid metabolism disorders, hypertension, and abdominal weight gain are among the risks to monitor. Preventing these risks involves physical activity, a balanced diet, and regular medical follow-up — all of which a comprehensive health check makes possible.

Bone health and fracture risk

Oestrogen deficiency accelerates bone loss (5). It is the leading cause of osteoporosis in menopausal women, with an associated increase in the risk of fractures (wrist, vertebrae, femoral neck). Measuring vitamin D levels, calcaemia, and, if necessary, a bone density scan can help assess this risk. Early prevention (calcium intake, vitamin D, weight-bearing physical activity) makes a real difference to quality of life in the decades that follow.

Mental health and quality of life

Hormonal fluctuations influence mood, sleep, and cognition (6). Anxiety and depressive disorders are more common during this period. Recognising these disorders as linked to perimenopause, rather than as a personal weakness, is often a relief in itself.

During perimenopause, a hormone panel is not routinely recommended. Hormone levels, particularly FSH and oestradiol, can vary considerably from one cycle to the next, making the test unreliable and difficult to interpret.

The diagnosis of perimenopause and menopause is primarily clinical: it is based on age, symptoms experienced, and changes in cycles. Your GP or gynaecologist does not need a blood test to make this diagnosis — your lived experience is sufficient (7).

A hormone panel does, however, become relevant and indicated in the following situations:

• Early age (before 40): if suggestive symptoms appear before the age of 40, testing is necessary to confirm or rule out premature ovarian insufficiency (POI) (8)
• Infertility: to assess ovarian reserve and guide management.
• Conservative hysterectomy (uterus removed but ovaries retained): without periods as a reference point, hormone testing becomes the only way to assess ovarian function.

Please note: a single hormone measurement is not always sufficient to draw conclusions. Hormones fluctuate naturally from one cycle to the next, and even from one day to the next. Your doctor may recommend monitoring over several months if necessary. The interpretation of results always rests with the healthcare professional.

Which tests are generally carried out? (9)

• FSH (follicle-stimulating hormone): when the ovaries slow down, the pituitary gland produces more FSH to stimulate them. A high FSH level may indicate advanced menopause.
• Oestradiol: it is the main oestrogen produced by the ovaries. Its levels tend to decline at menopause, which explains many of the symptoms.
• Progesterone: produced after ovulation, it tends to decrease when ovulation becomes irregular.
• AMH (anti-Müllerian hormone): a reflection of ovarian reserve.
• TSH (thyroid): useful for avoiding confusion between thyroid symptoms and menopause.
• FBC, ferritin, vitamin D: to assess general health and certain deficiencies.

The results of a test should always be interpreted within their broader context: your age, your symptoms, your medical history, your cycle. A result that is "within the normal range" does not necessarily mean everything is fine, and the reverse is equally true — some out-of-range results may have no clinical consequences. Your GP or gynaecologist remains the best person to guide you through this, make a diagnosis, and advise on the appropriate course of action.

A hormonal assessment is not an end in itself: it is a starting point. Depending on your results, your symptoms and your personal history, several avenues of support can be considered with your doctor.

HRT (hormone replacement therapy)

HRT generally combines an oestrogen and a progestogen in women who have not had a hysterectomy. Its benefits are recognised for climacteric symptoms (= the range of symptoms linked to the decline in oestrogen levels) and for osteoporosis prevention. Recent studies clarify its indications, its effects and the profile of patients for whom the benefit-risk ratio is most favourable. (10)

HRT is not suitable for all women. Certain medical histories, such as hormone-dependent cancer or thromboembolic risk, contraindicate this treatment. It is a shared decision made with a healthcare professional, and never something to pursue independently.

Non-hormonal approaches

Many patients choose, or need to turn to, non-hormonal approaches: phytotherapy treatment, regular physical activity, nutritional support, stress management, sleep, and targeted supplements. These approaches can genuinely improve day-to-day quality of life, especially when combined (11).

Long-term follow-up

Whatever path is chosen, regular cardiovascular, bone and gynaecological monitoring is invaluable. The perimenopause marks the beginning of a new phase in a woman's life; it is less about "treating" and more about navigating these years with care and attention (12).

There are two ways to carry out this assessment. Here is an overview of the differences:

With a prescription

• Covered by the National Health Service
• Prescribed and interpreted by a doctor
• Requires a medical appointment
• Tests selected by the doctor
• Elements tested: according to the medical prescription

Without a prescription

• Available directly at the laboratory
• No prior medical appointment needed
• Ideal as a first step
• Results to share with your doctor
• Elements tested: often FSH and oestradiol

A blood panel without a prescription does not replace a medical consultation — it prepares for one, and often makes it easier. Arriving at your doctor's with results in hand means arriving with concrete information to build a real dialogue, save time, and find the right course of care more quickly.

Jolly Mama's Péri Essentials is a multivitamin designed to support you through perimenopause on a daily basis. Its formula helps replenish essential nutrients and reduce fatigue, whilst also providing bacopa, an ingredient recognised for supporting concentration and memory – two areas that can be put to the test during perimenopause.