If you're serious about hormone optimisation, you need to start with the foundations: sleep, training, stress management, and nutrition. Supplements build on those, not replace them.
But used correctly, certain supplements have solid evidence for supporting female hormonal health. This guide breaks them into tiers based on evidence strength and relevance.
Tier 1: Foundational (everyone should consider these)
These are supplements with strong evidence and broad relevance. If you're optimising hormones, you're probably deficient in at least one of these.
Magnesium Glycinate
The case: Magnesium deficiency is endemic in the UK. Most women don't get adequate amounts from food (you'd need consistent red meat, nuts, and seeds to hit targets). Magnesium is co-factor in over 300 enzymatic reactions, including those producing oestrogen and progesterone.
Evidence: Magnesium improves sleep quality, reduces anxiety, alleviates PMS symptoms, and supports insulin sensitivity. Multiple trials show that women supplementing magnesium (200–400 mg daily) report better sleep and reduced mood symptoms across the cycle.
Dose: 300–400 mg daily, taken at night (it's mildly sedating). Magnesium glycinate is the most absorbable form and won't cause digestive upset like magnesium oxide.
Why glycinate specifically: The glycine is bound to the magnesium, improving absorption and providing the additional benefit of glycine for sleep and mood. It's worth the extra cost over cheaper forms.
Timeline: 4–6 weeks to feel effects, particularly for sleep.
Where: Bulk, MyProtein, Amazon (third-party verified), health food shops.
Vitamin D3 + K2
The case: The UK is grey. Most people are insufficient in vitamin D (below 50 nmol/L is deficient; below 75 is insufficient). Vitamin D is essential for immune function, bone health, and hormone metabolism. Low D correlates with higher fracture risk, worse mood, and reduced oestrogen signalling.
Evidence: Solid. Vitamin D deficiency impairs multiple aspects of health. Supplementation improves bone density, mood, and immune function. For women over 40, adequate vitamin D is non-negotiable.
K2 works synergistically with D3: it activates osteocalcin (a protein that anchors calcium into bone) and directs calcium deposition to bone rather than soft tissue. Together, they're more effective than D3 alone.
Dose:
- Vitamin D3: 1000–2000 IU daily (25–50 mcg). UK winter may require 2000–4000 IU depending on skin tone and sun exposure
- K2 (MK-7): 90–180 mcg daily
Timeline: 4–8 weeks for blood levels to rise meaningfully; months for bone benefit.
Where: Bulk, MyProtein, Amazon, health shops. Look for combined D3+K2 products to simplify dosing.
Testing: Ask your GP to test 25-hydroxyvitamin D. Optimal range is 75–150 nmol/L. If you're below 50, supplementation is essential.
Omega-3 (EPA + DHA)
The case: Most UK diets are deficient in omega-3 and excessive in omega-6. This creates a pro-inflammatory environment. Oestrogen is anti-inflammatory; as it declines with age, inflammation creeps in. Omega-3 directly counters this.
Evidence: Strong. EPA and DHA reduce inflammation, support cardiovascular health (increasingly important as oestrogen declines), support mood and cognitive function, and reduce joint pain. The ratio of EPA to DHA matters for mood (higher EPA) and neurological health (higher DHA).
Dose: 1000–2000 mg combined EPA+DHA daily. A standard fish oil supplement provides roughly 300 mg per 1000 mg capsule; you'll need 3–6 capsules daily. Alternatively, algae-based supplements (for vegetarians) or krill oil (slightly more bioavailable than fish oil).
Quality: Choose third-party tested brands. Fish oil oxidises easily and rancid omega-3 is pro-inflammatory. Brands like Bare Biology have excellent testing standards.
Where: Bare Biology (premium, mail order), Bulk, MyProtein, health shops.
Tip: Store in the fridge and take with meals to minimise any fishy aftertaste and optimise absorption.
Tier 2: Targeted (address specific issues)
These are effective for specific complaints, not broad foundational support.
Ashwagandha (KSM-66)
The case: Chronic stress elevation suppresses GnRH and LH, directly reducing oestrogen and testosterone. Ashwagandha (specifically the KSM-66 extract) reduces cortisol and improves stress resilience without sedating you.
Evidence: Multiple trials in stressed populations show cortisol reduction, improved mood, and better sleep. For perimenopausal women particularly, ashwagandha reduces hot flush severity and improves sleep quality.
Dose: 300–500 mg KSM-66 extract daily. KSM-66 is the specific extract used in most trials; other extracts are less well-studied.
Timeline: 4–8 weeks to feel effects.
Who: Women with high stress, anxiety, or perimenopausal hot flushes.
Where: Bulk, MyProtein, health shops (look specifically for KSM-66 extract).
Soy Isoflavones
The case: Phytoestrogens—plant compounds that weakly bind oestrogen receptors. Soy is the richest source. For perimenopausal women experiencing hot flushes, isoflavones provide modest but real relief.
Evidence: Meta-analyses show roughly 20–30% reduction in hot flush frequency and severity compared to placebo. It's not dramatic, but it's consistent.
Dose: 40–100 mg isoflavones daily. A typical supplement provides 40–50 mg per serving.
Timeline: 6–8 weeks before assessing benefit.
Who: Perimenopausal women with hot flushes.
Note: If you have a history of oestrogen-sensitive breast cancer, discuss phytoestrogens with your oncologist. The evidence suggests they're safe, but individual risk varies.
Where: Health shops, Amazon, Bulk.
Red Clover
The case: Similar to soy—a phytoestrogen source. Some evidence suggests red clover may be equally effective as soy for hot flushes, with slightly different isoflavone profiles.
Evidence: Several trials show modest reduction in hot flush severity. Comparable to soy but with slightly different tolerability for some women.
Dose: 80 mg isoflavones daily.
Timeline: 6–8 weeks.
Where: Health shops, Amazon.
Note: You don't necessarily need both soy and red clover. Pick one and stick with it for 8 weeks before deciding.
Iron
The case: UK iron deficiency rates in women are high, particularly if you're still menstruating. Iron deficiency causes fatigue, brain fog, poor exercise performance, and mood disruption. For perimenopausal and post-menopausal women, iron remains important for cognitive function and energy.
Evidence: Solid, obvious evidence—if you're iron deficient, supplementation fixes it.
Who needs it: Women with heavy periods, vegetarians/vegans, women experiencing fatigue or brain fog.
First step: Get tested. A simple ferritin test tells you iron stores. Optimal range for women is roughly 50–150 mcg/L. Below 30 is deficient.
Dose: Depends on severity, but typically 18 mg daily for women. Heme iron (from meat) is more absorbable than non-heme (from supplements), but if you're deficient, supplementation works.
Form: Iron bisglycinate is well-absorbed and gentler on the stomach than iron sulphate. Take with vitamin C (orange juice) to enhance absorption.
Where: Health shops, Boots, Amazon—but ideally, test first and supplement based on need.
Inositol (myo-inositol)
The case: For women with PCOS (polycystic ovary syndrome), inositol has strong evidence for improving insulin sensitivity, supporting ovarian function, and reducing androgen excess.
Evidence: Multiple trials show myo-inositol (the most common form) improves insulin resistance, reduces excess testosterone, and improves ovarian function. It also supports healthy oestrogen and progesterone cycling.
Who needs it: Women with PCOS diagnosis, or women with symptoms suggestive of insulin resistance (difficulty losing weight, fatigue after meals, irregular periods).
Dose: 2–4 grams myo-inositol daily, often taken in divided doses.
Timeline: 3–6 months for full benefit.
Where: Bulk, MyProtein, specialist supplement retailers.
Note: Some newer formulas combine myo-inositol with d-chiro-inositol in a 40:1 ratio, which may be marginally more effective. The evidence is still emerging.
Tier 3: Advanced or condition-specific
These are for specific situations or in response to specific health issues.
DHEA
The case: Covered in detail in our dedicated DHEA guide. For post-menopausal women with low DHEA and low libido or energy, DHEA supplementation has real evidence for benefit.
Dose: 25–50 mg daily.
Where: Bulk, MyProtein, health shops.
Timeline: 6–12 weeks for meaningful benefit.
Vitex (Agnus Castus)
The case: Herb traditionally used for PMS and luteal phase support. It's believed to support progesterone production or sensitivity.
Evidence: Modest. Several trials show a roughly 10–20% improvement in PMS symptoms. It's not dramatic, but it's consistent. Evidence is weaker than magnesium or omega-3, but it's not harmful.
Dose: 300–500 mg daily, typically taken in the luteal phase (days 15–28 of your cycle), though some practitioners recommend year-round.
Timeline: 2–3 cycles to assess benefit.
Who: Women with significant PMS symptoms who've optimised Tier 1 and 2 options.
Note: Some women report excellent results; others notice nothing. It's worth trying for 2–3 cycles, but don't expect miracles.
Where: Health shops, Amazon.
Practical protocol for 35–50-year-old women
If you're building a stack from scratch, start here:
Month 1–3: Magnesium glycinate + Vitamin D3 + K2 + Omega-3. These are foundational; everyone benefits.
Month 2–3 onwards: Assess. If you're still experiencing hot flushes, add soy isoflavones or red clover. If stress is high or sleep is disrupted, add ashwagandha. If you're fatigued and haven't been tested for iron, get tested and supplement if needed.
Month 4+: If you're perimenopausal or post-menopausal, consider DHEA if other interventions haven't resolved libido or energy issues. If PCOS is present, add inositol.
Don't start everything at once. You won't know what's working. Start with foundations, give them 4–6 weeks, then add one thing at a time.
Testing before you supplement
Before you go all-in on supplementation, get basic bloodwork:
- Iron (ferritin): If you're fatigued, this is the first thing to rule out
- Vitamin D (25-hydroxyvitamin D): Tells you if supplementation is necessary
- Thyroid (TSH, free T4): Thyroid dysfunction mimics perimenopause; essential to rule out
- Testosterone, DHEA-S: If libido is low or energy is poor, check these
- Fasting glucose and insulin: If weight loss is difficult, insulin resistance may be present
Good bloodwork prevents wasting money on supplements you don't need and catches real underlying issues.
Final note
Supplements are leverage on top of the fundamentals. If your sleep is terrible, your training is inconsistent, and your stress is chronic, supplements won't rescue you. Fix the big things first—sleep, training, stress—then add supplementation for the remaining gaps.
But used correctly, this stack addresses the most common hormonal issues in women over 35. Most women report meaningful improvements in energy, mood, sleep quality, and libido within 8–12 weeks of consistent supplementation paired with solid foundations.
Seb covers hormone optimisation and evidence-based health for adults over 30. He writes for maleoptimal.co.uk and maintains a focus on clinical evidence, practical implementation, and what actually works.
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