Blood test for hormones: how to prepare for an accurate result
Why you can't donate hormones "on the go"«
Anya decided to check her thyroid hormone levels because she had been feeling tired and lethargic lately. In the morning before donating blood, she drank coffee and rushed to the lab at the last minute. The test results were «bad,» but after a repeat test, with proper adherence to the recommendations, everything returned to normal. This is not uncommon. Hormonal indicators are very sensitive to lifestyle, emotions, and even time of day.
«"I always emphasize to patients: hormones are not blood sugar. They respond to stress, insomnia, and physical activity. The accuracy of the result begins with proper preparation,", — says endocrinologist Olga Melnyk.
Why take hormone tests?
Hormones control everything from sleep and appetite to fertility, immunity, and mood. Hormone testing can help:
reveal thyroid disorder (hypo- or hyperthyroidism)
establish the cause infertility, irregular cycle or lack of ovulation
diagnose polycystic ovary syndrome (PCOS)
verify adrenal gland function (cortisol level, ACTH)
find out why they occur acne, hirsutism, obesity
reveal endocrine disorders in adolescents (delayed or accelerated development)
Key hormones and indications for analysis
| Hormone | Organ/system | When is it prescribed? |
|---|---|---|
| TSH, T3, T4 | Thyroid | Decreased energy, weight change, knots, cold/heat |
| FSH, LH, Estradiol | Reproductive system | Cycle disorders, infertility, menopause |
| Prolactin | Pituitary | Milk secretion, headache, menstrual irregularities |
| Testosterone | Gonads | Hirsutism, decreased libido, erectile dysfunction |
| Progesterone | Ovaries | Ovulation assessment, pregnancy preparation |
| Cortisol, ACTH | Adrenal glands | Chronic stress, high blood pressure, anxiety |
| Insulin, Glucose | Pancreas | Suspected diabetes, metabolic syndrome |
Preparing for a blood test for hormones: step by step
1. Nutrition and fasting
Surrender definitely on an empty stomach — last meal 8–12 hours ago
You can only drink clean water
Avoid fatty, sweet and alcohol foods 1–2 days before delivery
2. Physical activity
Per day — no intense sports, training or hard work
On the day of delivery - arrive early, sit for 10–15 minutes, calm down
3. Stress and sleep
Avoid worries, don't argue on the way to the lab
Bad sleep changes level cortisol і prolactin
Quote:
«"Although it may seem like a small thing, even a night without sleep increases prolactin levels and can lead to misdiagnoses,", — says endocrinologist Taras Zinchenko.
4. Medications and dietary supplements
Tell your doctor if you are taking:
hormonal drugs
thyroxine
corticosteroids
iodine-containing drugs
vitamins (especially groups D, E)
Do not stop taking it on your own! Some hormones are taken while taking medications (for example, to monitor therapy)
5. Menstrual cycle in women
| Hormone | Cycle day |
|---|---|
| FSH, LH | Day 3–5 |
| Estradiol | Day 5 or 21 (depending on the goal) |
| Progesterone | Day 21–23 |
| Prolactin | any day, but in the morning and at rest |
| Testosterone | follicular phase (day 3–8) |
Advice: donate hormones until 10:00 am, when their level is most stable.
Typical patient mistakes
Drank coffee/tea or had a snack before the test
Not warned about taking hormonal contraceptives
Passed analysis on any day of the cycle without approval
Too nervous before blood draw
Passed the test after physical exertion or illness
«"80% of incorrect results are preparation errors. Neither the device nor the laboratory technician is to blame here,", — notes the head of the laboratory, Hanna Kolesnyk.
What else is worth considering?
After a cold or SARS it is better to wait 7–10 days
If you plan resubmission — do it at the same time of day
Don't compare your results with others - hormonal levels are individual.
Prepare for hormone analysis — it is not difficult, but important. Only following the recommendations will allow the doctor to get reliable information and choose a treatment that really works. Sometimes the result depends not on the laboratory, but on the cup of coffee drunk in the morning.
Director of Medi Lab Plus LLC, a doctor of the highest category. Has over 45 years of practical experience in medicine and laboratory diagnostics. Founder and head of the laboratory since 2007. More details…