Fertility hormones: tests, timing and GP guidance
Fertility is influenced by a complex interaction of hormones, reproductive organs, general health, age and lifestyle factors. Hormone testing can be helpful in some situations, but it does not provide a complete picture of fertility on its own.
This page explains how GPs approach fertility hormone assessment, which tests are commonly used, what results can and cannot tell us, and when further investigation or referral is appropriate.
These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help, please book an appointment with one of our GP’s.
The GP approach to fertility concerns
Initial assessment of fertility usually focuses on:
- How long pregnancy has been attempted
- Menstrual regularity and cycle pattern
- Ovulation symptoms
- Medical history and medications
- Lifestyle factors such as weight, smoking and alcohol
- Both partners, where relevant
Hormone testing is considered when it is likely to provide useful information and guide next steps.
Female fertility hormones explained
Follicle-stimulating hormone (FSH)
FSH plays a role in ovarian stimulation and egg development.
- Often measured early in the menstrual cycle
- Higher levels may suggest reduced ovarian reserve, but results must be interpreted with age and cycle timing in mind
Luteinising hormone (LH)
LH triggers ovulation.
- Abnormal patterns may be seen in conditions such as polycystic ovary syndrome (PCOS)
- LH levels alone do not diagnose fertility problems
Oestradiol
Oestradiol reflects ovarian hormone activity.
- Helps interpret FSH results
- Levels vary throughout the cycle
Anti-Müllerian hormone (AMH)
AMH is often used as a marker of ovarian reserve.
- Reflects the quantity, not quality, of eggs
- Does not predict natural conception reliably
- More useful in assisted fertility planning than routine screening
Progesterone
Progesterone is used to confirm ovulation.
- Usually measured in the second half of the cycle
- A normal result suggests ovulation has occurred
Male fertility hormones explained
Hormone testing in men is considered when there are concerns about sperm production or sexual function.
Testosterone
Low testosterone can affect libido and energy but does not always correlate with fertility.
FSH and LH
These hormones help assess testicular function.
- Abnormal results may suggest impaired sperm production
- Interpretation often requires specialist input
Hormone tests do not replace semen analysis, which remains the primary investigation for male fertility.
Timing matters in fertility hormone testing
Many fertility hormone tests are time-sensitive.
Examples:
- FSH, LH and oestradiol are usually measured early in the menstrual cycle
- Progesterone is measured after ovulation
- AMH can be measured at any time
Incorrect timing can lead to misleading results.
What fertility hormone tests can and cannot tell you
What they can help with
- Identifying ovulation patterns
- Suggesting reduced ovarian reserve
- Highlighting hormonal conditions such as PCOS
- Guiding referral decisions
What they cannot do
- Guarantee future fertility
- Predict the chance of natural conception
- Replace assessment of fallopian tubes or sperm quality
- Fully explain unexplained infertility
Normal hormone results do not always mean fertility will be straightforward, and abnormal results do not always prevent pregnancy.
When fertility hormone testing is usually considered
A GP may consider hormone testing if:
- Pregnancy has not occurred after 12 months of trying (or 6 months if over 35)
- Periods are irregular or absent
- There are symptoms suggestive of hormonal conditions
- There is a known history of reproductive or endocrine disease
Early testing without indication can cause unnecessary anxiety.
When referral to specialist care is appropriate
Referral may be considered if:
- Hormone results are significantly abnormal
- Ovulation is not occurring
- There are male factor concerns
- There is a history of pelvic surgery, infection or endometriosis
- Pregnancy has not occurred despite appropriate time and assessment
GPs work to ensure referrals are timely and appropriate.
Emotional wellbeing and fertility
Fertility concerns can be emotionally challenging. Hormone testing can sometimes add stress rather than clarity if not properly explained.
GP support focuses on:
- Clear interpretation of results
- Avoiding unnecessary testing
- Supporting mental wellbeing alongside physical assessment
When to seek GP review
Consider GP review if:
- You are concerned about fertility or hormone results
- Your menstrual cycle is irregular or absent
- You have been trying to conceive without success
- You want guidance on appropriate testing or referral
Further Reading and Hub Links
Visit our Hormone Health hub or browse more health topics in the AccessGP Knowledge Base.
If you have fertility concerns or would like help deciding whether hormone testing is appropriate, a GP can assess your situation and advise on next steps.
Last reviewed by Dr Zamiel Hussain, GMC registered GP
Updated: 31 December 2025