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Woman Working Thoughtfully

The Science

Why sex-specific formulation matters. How we develop supplements based on research conducted on women

Your supplements were probably tested on men.

For decades, women were actively excluded from clinical trials. The assumption was that male biology could stand in for everyone. That assumption was wrong — and the supplement industry still has not caught up.
The result? Products that do not account for how women’s bodies actually process nutrients, respond to stress, recover from exercise, or change across life stages.

STATS CALLOUTS 

• Only  around 34% of exercise and health research participants are wome


• Hormonal fluctuations are rarely accounted for in supplement efficacy studies


• Perimenopause can begin in your late 30s — years before most women expect it


• Most supplement dosages on the market are derived from studies on young male subjects

Why Sex-Specific Formulation Matters

Women metabolise nutrients differently to men. Hormonal changes across life stages fundamentally alter nutritional needs. What works for a 25-year-old man does not necessarily work for a 45-year-old woman — and yet that is exactly the assumption most supplement brands make.


Key areas where women’s needs diverge: bone density maintenance (oestrogen decline accelerates bone loss), iron absorption (critical before menopause, less so after), magnesium requirements (higher in active women and during hormonal transitions), adaptogen responses (cortisol regulation differs by sex), and B-vitamin metabolism (methylation capacity varies significantly).


These are not subtle differences. They are the reason a generic multivitamin or a supplement designed for a 25-year-old male athlete does not serve you properly.

Our Formulation Approach

Evidence from women, where it exists
We prioritise research conducted on female subjects. Where mixed-population studies are the best available, we account for known sex-based differences in metabolism and response.


Dosages aligned with female-specific research
Not the minimum effective dose from a male-subject study. The dose that the evidence suggests works for women’s physiology.


Life-stage formulation
Your nutritional needs at 35 are different to your needs at 50. Our products are designed around the hormonal profiles and physiological priorities of each stage.


Full transparency
Every ingredient and every dosage is on the label. No proprietary blends. No hidden formulas. You can see exactly what you are taking and verify it against the research yourself.

The Life Stages

Active 30s (30–39)

Peak performance years, but this is when the first hormonal shifts begin, bone density peaks and starts to plateau, and recovery demands quietly increase. Focus: foundation nutrients, energy support, stress adaptation.

Perimenopause (38–50)

Fluctuating oestrogen and progesterone bring disrupted sleep, brain fog, mood changes, and unpredictable energy. Focus: hormonal balance, mood support, bone protection, sleep quality.

Menopause (45–55+)

Cycles end, oestrogen declines significantly, metabolic shifts accelerate. Focus: hot flush support, joint health, cardiovascular support, cognitive function.

50+ Vitality (55+)

Post-menopause brings specific concerns around bone density, cognitive changes, and immune resilience. Focus: bone strength, cognitive support, sustained energy, cardiovascular health.

©2026 xSpan Labs Ltd. All rights reserved.

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