Hormone Tests for Women: Which Blood Tests to Take and On Which Day of Your Cycle
By Femly Health Editorial Team · 14 November 2026
Hormone tests for women are blood tests. They check hormones such as FSH, LH, estradiol, progesterone, prolactin and thyroid hormone. Each test has its own best day. Some work best early in your cycle, and progesterone is timed near the end. Your doctor decides which tests you need and when to take them.
Do you need a hormone test at all?
Not every woman with a period problem needs a long list of tests. A doctor usually starts by asking about your periods, weight changes, acne, hair growth, stress, sleep and medicines. Then they decide which tests make sense.
Tests are more likely to help if your periods are irregular or missing. They can also help if you have been trying to get pregnant for some time. The same is true for new acne, extra facial hair or hair fall. Our guide on what counts as irregular periods can help you see where you fit.
For irregular periods, a US group of gynaecologists called ACOG lists tests such as prolactin, LH, FSH and TSH. You can read a summary in this review of hormonal testing in adult females. It also notes that PMOS (PCOD/PCOS) may be one cause when irregular periods come with high androgens. Androgens are male-type hormones.
Why does the day of your cycle matter?
Your hormones rise and fall through the month. A number that is normal on day 3 can look very different on day 21. That is why labs and doctors ask when your last period started.
Count the first day of full bleeding as day 1. Light spotting before the flow does not count. If you are unsure, tell the doctor or lab exactly what you noticed.
Which hormone tests are done on which day?
Here is a simple guide to common tests. Timing can vary between doctors and labs, so always follow the advice you are given.
| Test | What it looks at | Usual timing |
|---|---|---|
| FSH, LH and estradiol | How the brain signals the ovaries, and a baseline of ovary activity | Early in the cycle, often between day 2 and day 5 |
| Progesterone | Whether ovulation likely happened | About 7 days before your next expected period |
| TSH (thyroid) | How well your thyroid is working | Usually any day of the cycle |
| Prolactin | A hormone that can stop ovulation when it is high | Your doctor or lab will tell you the best time |
| Fasting sugar and insulin | How your body handles sugar | After an overnight fast, as advised |
| Testosterone and DHEAS | Male-type hormones that can cause acne and facial hair | Your doctor will advise the day |
For the first group, an overview of the female hormone panel gives days 2 to 5. An NHS hospital leaflet on fertility tests says blood tests are usually taken on days 2 to 4. A separate progesterone test comes later. Both point to the early part of the cycle.
Is the "day 21 progesterone test" right for everyone?
Not always. Day 21 works only if your cycle is about 28 days long. The real aim is to test about seven days after you ovulate. That is also about seven days before your next period. This is explained in a guide to progesterone test timing.
If your cycle is 35 days, the test may fall around day 28. If your cycles vary a lot, the timing is hard to guess. Your doctor may ask you to track your cycle, use ovulation strips, or repeat the test.
Our article on finding your fertile window when your cycle is not 28 days explains how to estimate ovulation.
What if your periods are very irregular or have stopped?
If you get a period only every few months, there may be no clear day 2 to test on. Your doctor may rule out pregnancy first. Then they may suggest tests that do not depend on the cycle day. Or they may ask you to test after a period starts.
A missing period has many possible causes, including thyroid problems, high prolactin, PMOS, stress and low body weight. Your doctor looks at the whole picture. You can read more about two common causes in our guides on high prolactin and stress and cortisol.
Which tests go with which concern?
There is no single test that sorts out every hormone problem. This table shows what doctors often consider for common concerns. It is not a list to order on your own.
| Your concern | Tests a doctor may consider | Good to know |
|---|---|---|
| Irregular or missed periods | Pregnancy test, TSH, prolactin, FSH, LH | Often the first step |
| Possible PMOS | Blood tests plus an ultrasound, and a review of symptoms | No single test confirms it. See how PMOS is diagnosed |
| Trying to get pregnant | Early-cycle bloods, progesterone, sometimes AMH | See what a low AMH result means |
| Tiredness, weight change, hair fall | TSH and related thyroid tests | See TSH results explained |
| Acne and extra facial hair | Androgen tests, and sometimes sugar and insulin | See hormonal acne in women |
How can you prepare for a hormone blood test?
A little planning helps you get a result your doctor can use. Here are the steps.
- Note the first day of your last period, and the date of the one before. A phone calendar is enough.
- Ask whether you need to fast, and for how long. Some tests, like fasting sugar and insulin, need it. Others do not.
- Tell your doctor and the lab about any medicines or supplements you already use. Any change to them is your doctor's decision.
- Book the test for the day your doctor advised. If the day falls on a weekend or holiday, call and ask what to do instead of guessing.
- Keep your report and the cycle day on which you took it. A result is easier to read with that date.
Are saliva tests and home hormone kits reliable?
Many online brands sell saliva or finger-prick "hormone balance" kits. Major medical groups do not support salivary hormone testing. A medical policy summary says three major groups advise against it. They are ACOG, the North American Menopause Society and the Endocrine Society.
The Endocrine Society's concern is that these assays are not standardised and have no accepted reference range. In plain words, a number from such a kit is hard to compare with anything. A standard blood test from a good lab, read by a doctor, is a safer choice.
How should you read your results?
A report shows your number next to a "reference range". Being slightly outside the range does not always mean something is wrong. Being inside the range does not always mean everything is fine. Doctors look at your symptoms, your cycle, your age and sometimes a repeat test.
Try not to compare your report with a friend's, or with a chart online. Ranges differ between labs and cycle phases. Take the report to your doctor and ask what each result means for you.
Good questions to ask include these:
- Was this test taken on the right day for my cycle?
- Do I need to repeat any test?
- Do these results explain my symptoms, or do I need other tests?
- Could anything I use have changed the result?
How can Femly help with hormone test questions?
Many women get a stack of reports and no clear explanation. At Femly Health, a doctor can evaluate your concern and look at your reports. You get guidance on which tests may help next. You can start with an Online Doctor Consultation for Women.
Femly's clinical nutrition team can also support you with food and lifestyle guidance for hormonal and metabolic health. This works alongside your doctor's care. It does not replace tests or medicines. You can explore more topics in our Hormonal Balance hub.
When to see a doctor
See a doctor if your periods are irregular for three months or more. Also go if you miss periods and are not pregnant. Other reasons include trying to get pregnant without success, new acne, extra facial hair, milky nipple discharge or sudden weight change.
A report alone is not enough to decide on medicines. Any medicine decision belongs to your doctor. Your doctor can choose the right tests and explain your results.
Frequently asked questions
Which hormone tests should a woman get done?
It depends on your symptoms. For irregular periods, doctors often consider TSH, prolactin, FSH and LH. For trying to conceive, they may add progesterone and sometimes AMH. A doctor picks the list for you, so you do not need every test.
On which day of the period should I do hormone tests?
FSH, LH and estradiol are usually done early in the cycle, often between day 2 and day 5. Day 1 is the first day of full bleeding. Some tests, like TSH, can usually be done on any day. Always follow your doctor's advice.
When should I take the progesterone test?
Progesterone is usually taken about seven days before your next expected period. In a 28-day cycle that is day 21. If your cycle is longer or varies, the day will be different, so ask your doctor to set it for you.
Can I take a hormone test on any day of the month?
Some tests, such as TSH, are usually fine on any day. Others, like FSH, LH, estradiol and progesterone, depend on the cycle day. A result taken on the wrong day can be hard to read.
Do I need to fast for hormone tests?
Not for all of them. Fasting is usually needed for sugar and insulin tests. Other hormone tests may not need it. Ask your doctor or lab when you book the test.
How do I do a hormone test if I do not get periods?
If you rarely get periods, the cycle day cannot guide timing. Your doctor may first rule out pregnancy. They may then choose tests that do not depend on the day, or time the test after a period starts.
Is a full hormone panel needed for PMOS (PCOD/PCOS)?
No single test confirms PMOS. A doctor looks at your periods, signs of high androgens, blood tests and often an ultrasound. They also rule out other causes, like thyroid problems and high prolactin.
Are saliva hormone tests accurate?
Major medical groups, including ACOG, the North American Menopause Society and the Endocrine Society, advise against salivary hormone testing. These tests are not standardised and have no accepted reference range. A standard blood test read by a doctor is a safer choice.
Can supplements change my hormone test results?
Yes, some can. High-dose biotin, found in many hair and nail products, can make certain thyroid and hormone tests read falsely high or low. Tell your doctor and lab about every supplement you use. Any change to a supplement is a decision for your doctor.
Do birth control pills affect hormone test results?
Hormone medicines such as birth control pills can change hormone levels. This can make results harder to read. Tell your doctor about them before testing. Any change to a medicine is your doctor's decision.
What should I do if my hormone report shows a value outside the range?
Do not panic. A value slightly outside the range does not always mean a problem. Reference ranges differ between labs and cycle phases. Take the report to your doctor, who will read it with your symptoms and may repeat the test.