Progesterone
| Clinical | Optimal | |
|---|---|---|
| Male | 0.7 - 4.3 nmol/L | 0.7–4.3 nmol/L |
| Female | Follicular: <5.4 nmol/L; Ovulation: 1.3-5.4 nmol/L; Luteal: 6.9-80.0 nmol/L; Postmenopausal: <1.3 nmol/L | 5.0–75.0 nmol/L (luteal phase, day 21) |
What is Progesterone?
Progesterone is a steroid hormone produced primarily by the ovaries following ovulation, with smaller amounts produced by the adrenal glands. In men, the testes produce small quantities. It plays a central role in the menstrual cycle, preparing the uterine lining for potential pregnancy and supporting early gestation.
Progesterone levels vary significantly throughout the menstrual cycle. They are lowest during the follicular phase (first half of the cycle), rise sharply after ovulation during the luteal phase, and then fall again if pregnancy does not occur, triggering menstruation. This cyclical pattern means timing of the blood test is crucial for meaningful interpretation.
Beyond reproduction, progesterone influences mood, sleep, bone health, and the cardiovascular system. It has calming effects on the brain and is sometimes referred to as the 'relaxing hormone' due to its interaction with GABA receptors.
Why Progesterone Matters for Your Health
Progesterone is vital for fertility and reproductive health, but its importance extends well beyond conception. Adequate progesterone levels are associated with better sleep quality, reduced anxiety, and improved bone density. It also helps counterbalance the effects of oestrogen, maintaining a healthy hormonal equilibrium.
In the context of longevity, progesterone deficiency — particularly relative to oestrogen (a state sometimes called oestrogen dominance) — has been linked to increased risk of certain health concerns including endometrial issues, breast tenderness, and mood disturbances. Tracking progesterone is especially valuable for women in their late 30s and 40s, when levels naturally begin to decline.
For men, while progesterone is present in much smaller amounts, it plays a role as a precursor to other hormones and may influence prostate health and nervous system function.
Progesterone& Your Wearable Data
Progesterone is the primary hormone of the luteal phase (second half of the menstrual cycle) and plays crucial roles in pregnancy, mood regulation, and sleep. Wearable devices can detect progesterone's physiological effects: the post-ovulatory rise in progesterone increases basal body temperature by 0.2-0.5 degrees Celsius, elevates resting heart rate by 2-5 bpm, and alters HRV patterns — all detectable through wearable sensors.
Exercise performance varies with progesterone levels across the menstrual cycle. High progesterone during the luteal phase increases core body temperature (trackable by wearables), ventilation rate, and metabolic demands. Your wearable may show higher heart rates at the same exercise intensities and reduced heat tolerance. Cycle-aware training guided by wearable data can optimise performance around these hormonal fluctuations.
Progesterone has sedative effects that influence wearable sleep metrics. Higher progesterone during the luteal phase often improves sleep onset latency and deep sleep on your wearable, while the premenstrual progesterone withdrawal can disrupt sleep. Tracking these sleep pattern changes alongside cycle phase data helps distinguish hormonal sleep variation from other causes of poor sleep.
What High Progesterone May Suggest
Elevated progesterone in women is most commonly associated with pregnancy. Outside of pregnancy, high levels may suggest an ovarian cyst, adrenal overproduction, or, rarely, congenital adrenal hyperplasia. In some cases, elevated progesterone may be seen with certain hormonal treatments.
Symptoms associated with very high progesterone can include bloating, breast tenderness, drowsiness, and mood changes. In men, significantly elevated progesterone is uncommon and may warrant investigation into adrenal or testicular function.
If results suggest unexpectedly high progesterone, your GP may recommend further hormonal assessment and imaging to identify the underlying cause.
What Low Progesterone May Suggest
Low progesterone is common and may suggest anovulation (failure to ovulate), luteal phase deficiency, or perimenopause. Results suggesting low progesterone in the luteal phase may be associated with difficulty conceiving or maintaining early pregnancy.
Symptoms of low progesterone can include irregular periods, heavy menstrual bleeding, premenstrual mood changes, insomnia, and anxiety. When oestrogen levels remain normal but progesterone is low, this imbalance may contribute to symptoms commonly attributed to oestrogen dominance.
Chronic stress is a significant contributor to low progesterone, as the body may preferentially produce cortisol from the same precursor hormones — a concept sometimes referred to as the 'pregnenolone steal.'
How to Optimise Your Progesterone
Food
Focus on foods rich in zinc (pumpkin seeds, grass-fed beef, oysters) and vitamin B6 (chickpeas, salmon, bananas), both of which support progesterone production. Include cruciferous vegetables such as broccoli, cauliflower, and Brussels sprouts to aid healthy oestrogen metabolism and improve the oestrogen-progesterone ratio. Consume adequate dietary fibre from whole grains, legumes, and vegetables to support hormone clearance. Healthy fats from avocados, nuts, and olive oil provide the cholesterol backbone needed for steroid hormone synthesis.
Lifestyle
Reduce chronic stress through regular meditation, yoga, or breathwork, as elevated cortisol directly competes with progesterone production. Maintain a healthy body weight, as both excess and insufficient body fat can impair ovulation and progesterone output. Prioritise 7–9 hours of quality sleep, since progesterone is produced in alignment with healthy circadian rhythms. Avoid overexercising, as excessive endurance training can suppress the reproductive axis. Limit exposure to xenoestrogens found in plastics, pesticides, and conventional personal care products.
Supplements
Vitex agnus-castus (chasteberry) has the strongest evidence base for naturally supporting progesterone levels by acting on the pituitary gland. Magnesium bisglycinate supports the stress response and may indirectly support progesterone by reducing cortisol. Vitamin C (500–1000 mg daily) has shown promise in some studies for increasing luteal-phase progesterone.
When to Speak to Your GP
See your GP if you are experiencing irregular or absent periods, difficulty conceiving, recurrent early pregnancy loss, or significant premenstrual symptoms. Women over 35 with declining fertility should discuss progesterone testing. If results suggest consistently low luteal-phase progesterone (below 16 nmol/L on day 21), further investigation of ovulatory function may be recommended.
References
- NHS. Infertility — Diagnosis. Updated 2024. nhs.uk
- NICE. Fertility problems: assessment and treatment. CG156. nice.org.uk
- BMJ. Coomarasamy A, et al. A randomized trial of progesterone in women with bleeding in early pregnancy (PRISM). N Engl J Med. 2019;380(19):1815-1824. pubmed.ncbi.nlm.nih.gov
- Lancet. Coomarasamy A, et al. Progesterone to prevent miscarriage in women with early pregnancy bleeding: the PRISM RCT. Health Technol Assess. 2020;24(33):1-70. pubmed.ncbi.nlm.nih.gov
Medical Disclaimer— This content is for general educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Omniwo Ltd is a wellness information service and is not a medical device, clinical laboratory, or regulated healthcare provider under MHRA guidelines. The “optimal ranges” presented on this page are based on published clinical guidelines (WHO, NICE, NHS) and peer-reviewed research; they represent functional wellness targets and may differ from standard laboratory reference ranges. Individual results should always be interpreted by a qualified healthcare professional (such as your GP) who understands your full medical history. Do not start, stop, or change any medication or supplement based solely on this information. If you are experiencing symptoms, seek medical attention promptly.