Hormone test Seoul: the right tests, at the right time

What a hormone test in Seoul can tell you

Hormones control energy, metabolism, mood, weight, sleep, sex drive, fertility and periods, so it is natural to wonder whether they are behind how you feel. A hormone test Seoul visit at VEI Clinic starts with your symptoms rather than a fixed menu. Dr. HyunSung Park, a board-certified internal medicine specialist, asks what has changed, when it started, and which medications or supplements you take, because many of these affect results.

Some hormones are stable through the day; others change by the hour, by season, or across the menstrual cycle. Getting the timing right is often the difference between a useful result and a misleading one.

If you already take thyroid medicine, testosterone, hormonal contraception or menopause treatment, bring the names and doses. We will advise whether to take your usual dose before the blood draw, since this can change how results are read.

Common hormone tests and what they show

Not everyone needs all of these. A man with low libido might start with morning testosterone, SHBG and prolactin, while a woman with irregular periods and acne might need FSH, LH, testosterone, DHEA-S, prolactin and insulin. Choosing tests this way keeps results meaningful and avoids chasing borderline numbers.

• Thyroid (TSH, free T4, sometimes free T3 and thyroid antibodies): for fatigue, weight change, feeling hot or cold, palpitations or hair changes
• Testosterone (total, with SHBG to estimate free testosterone): for low libido, erectile problems, low energy or loss of muscle in men; acne or excess hair growth in women
• Estradiol, FSH and LH: for irregular or absent periods, fertility questions, and suspected perimenopause or menopause
• Prolactin: for irregular periods, breast discharge or low libido
• Cortisol: when adrenal insufficiency or cortisol excess is suspected
• DHEA-S: an adrenal hormone, mainly useful when assessing excess androgen symptoms in women
• Fasting insulin and glucose, HbA1c: for insulin resistance, prediabetes or polycystic ovary syndrome (PCOS)

Timing your blood draw

Testosterone: levels are highest in the morning, so draw between about 7 and 10 a.m., ideally fasting. A single low result should be repeated on another morning before any diagnosis of low testosterone.

Women's hormones: FSH, LH and estradiol are usually checked on day 2 to 5 of the cycle (day 1 is the first day of full bleeding). Progesterone to confirm ovulation is checked about seven days before the expected period, around day 21 of a 28-day cycle. If you are on hormonal contraception, many results are not meaningful, so tell us.

Cortisol: a morning sample, often around 8 a.m., is standard for screening low cortisol. Other cortisol tests use late-night saliva or overnight suppression and are chosen only when needed. Thyroid: stop biotin supplements for a few days before testing, since biotin can distort some lab assays.

Who it suits, and what testing will not do

Hormone testing suits people with specific symptoms, those planning pregnancy, people with known thyroid disease or PCOS needing monitoring, and men or women considering whether symptoms fit perimenopause, menopause or low testosterone.

Hormone testing will not explain every symptom. Tiredness, weight gain and low mood have many causes, and normal ranges are wide. We do not recommend broad hormone panels for people without symptoms, and we do not prescribe hormones on the basis of a single borderline number. Saliva and urine hormone panels sold online often lack strong evidence for routine use. If treatment such as thyroid medicine or testosterone is considered, the doctor will explain the benefits and risks, or refer you to endocrinology, urology or gynecology for specialist care.

For people visiting Seoul for a short time, we can plan the timing of tests around your schedule and provide a written copy of results to share with your regular doctor at home.

Red flags

See a doctor promptly for a fast or irregular heartbeat with weight loss and tremor, a new neck lump, milky nipple discharge with headaches or vision changes, or periods that stop unexpectedly for three months or more.

Call 119 or go to an emergency room for severe weakness with vomiting, low blood pressure and confusion, which can signal an adrenal crisis, or for chest pain, fainting or very high fever with a racing heart.