What you'll learn:
- How estrogen affects insulin sensitivity across the menstrual cycle and into menopause.
- Why testosterone matters for women's metabolic function, not just men's.
- How the liver processes hormones and why liver enzymes can look different in women.
- Which markers to test to get a complete picture of metabolic and hormonal health.
How Estrogen Affects Insulin Sensitivity
Estrogen plays a significant protective role in metabolic function during reproductive years. Research in Endocrine Reviews shows that estrogen improves insulin sensitivity by promoting glucose uptake in skeletal muscle and suppressing hepatic glucose production (the liver releasing glucose into the bloodstream when it is not needed).
This is why insulin resistance tends to increase as estrogen declines during perimenopause and menopause. Women who previously had stable blood sugar markers often see HbA1c drift upward and fasting glucose become less predictable during this transition. The change is not primarily dietary or activity-related. It reflects the loss of estrogen's direct effect on insulin receptor signaling.
Estrogen also influences fat distribution. Higher estrogen levels favor subcutaneous fat storage (fat stored under the skin), while lower estrogen shifts the pattern toward visceral fat accumulation (fat stored around the organs). Visceral fat is metabolically active and produces inflammatory cytokines that worsen insulin resistance further.
Progesterone, Cortisol, and Metabolic Load
Progesterone has a more complex relationship with metabolic function than estrogen. In the luteal phase of the menstrual cycle (roughly days 15-28), progesterone rises and can mildly reduce insulin sensitivity. Research in Diabetes Care has documented that glucose tolerance is slightly worse in the luteal phase compared to the follicular phase in women with normal cycles.
Progesterone also competes with the same receptors as cortisol. When progesterone is low relative to cortisol, the cortisol signal becomes amplified, which increases gluconeogenesis (the liver making new glucose) and promotes fat storage. Women with low progesterone, which is common in perimenopause or with chronic stress, often show elevated morning fasting glucose even when daytime patterns appear normal.
For more on the cortisol-liver relationship that affects metabolic markers, understanding how cortisol and stress hormones interact is useful context.
Testosterone in Women: Metabolic Significance
Testosterone is present and metabolically important in women, though at much lower concentrations than in men. Low testosterone in women is associated with increased fat mass, reduced lean muscle, lower energy expenditure, and worsened insulin resistance. Women with PCOS (polycystic ovary syndrome), on the other hand, often have elevated androgens including testosterone, and this hormonal pattern is strongly associated with insulin resistance and elevated liver enzymes.
Testosterone testing for women is a useful addition to metabolic panels, particularly in women who have unexplained weight gain, fatigue, or blood sugar changes that do not track with lifestyle. It adds context that cholesterol and glucose measurements alone cannot provide.
How the Liver Processes Hormones and Why This Matters
The liver is responsible for metabolizing and clearing estrogen, progesterone, and testosterone from circulation. When the liver is under stress, whether from fat accumulation, alcohol, or metabolic dysfunction, hormone clearance becomes less efficient. This can lead to estrogen dominance relative to progesterone, even when estrogen levels themselves appear normal on a test.
Liver enzyme reference ranges differ by sex, and this distinction matters when interpreting results in women:
Women with elevated liver enzymes frequently also show disrupted estrogen metabolism, irregular cycles, or worsening PMS symptoms. The connection is bidirectional: hormonal imbalance increases liver load, and impaired liver function worsens hormonal imbalance. Tracking ALT and what elevated results mean is one of the clearest ways to see this dynamic.
Estrogen Testing and What Levels Reveal
Estrogen testing in the context of metabolic health typically looks at estradiol (E2), the most metabolically active form. Estradiol fluctuates throughout the cycle, so timing of the test matters. The follicular phase baseline (days 3-5 of the cycle) is a standard reference point.
In perimenopause and menopause, estradiol declines and becomes more variable before eventually stabilizing at lower postmenopausal levels. The metabolic impact of this transition is most measurable through the markers that estrogen was directly protecting: insulin sensitivity markers, triglycerides, LDL cholesterol, and visceral fat accumulation.
The Complete Metabolic and Hormonal Panel for Women
Assessing metabolic health in women comprehensively requires looking across both systems simultaneously. Separating hormones from metabolic markers misses the interactions that explain why results shift.
Useful markers to review together:
- HbA1c - average blood glucose over 2-3 months. Optimal <5.6%.
- Fasting glucose - reflects baseline glucose regulation. Optimal <100 mg/dL.
- Triglycerides - sensitive to estrogen status; tend to rise in perimenopause. Optimal <150 mg/dL.
- ALT and AST - liver cell stress, which reflects hormone processing efficiency.
- GGT - oxidative stress and liver load. Optimal for women <9 U/L.
- CRP - systemic inflammation, which estrogen decline tends to increase. Optimal <1 mg/L.
- Estradiol - baseline reference for cycle phase context.
- Total and free testosterone - relevant for PCOS assessment and lean mass maintenance.
- Cortisol - especially morning levels, which affect fasting glucose patterns. Optimal 6-18 ug/dL.
When to Test and How Often
The timing of testing matters for some of these markers. For hormone testing, a consistent cycle day (days 3-5 for follicular baseline, days 19-21 for luteal progesterone) reduces variability and makes trends more interpretable over time. For metabolic markers including liver enzymes and glucose, timing relative to the cycle matters less, but fasting status matters for glucose and triglycerides.
For women in perimenopause or with known PCOS, testing every 3-6 months gives enough resolution to see whether interventions are working before changes become entrenched.
Conclusion
Metabolic health in women is inseparable from hormonal health. Estrogen, progesterone, and testosterone all directly affect insulin sensitivity, fat distribution, and liver enzyme patterns. Testing these systems together, rather than in isolation, gives a more complete picture of what is actually driving the metabolic markers you see.
The goal is not a one-time snapshot. Tracking both hormone and metabolic markers over time, particularly through hormonal transitions, is where the most useful information lives.
