NEW DELHI: Losing hair despite “normal” blood work is a common frustration for many women. Doctors say the answer may not lie in routine reports—but in what’s happening inside the scalp.For female pattern alopecia, patients are typically advised a battery of tests—testosterone, free androgen index, thyroid function and nutritional work-ups such as vitamin levels. Yet, these often come back normal, leaving both patients and clinicians without clear answers.A study, published in an international journal of dermatology now offers an explanation. Researchers from Delhi’s Ram Manohar Lohia Hospital found that women with female pattern hair loss had significantly higher levels of a hormone marker called 3α-diol G—even when standard hormones like testosterone remained within normal range.Female pattern hair loss, which causes gradual thinning over the front and top of the scalp, affects a large number of women and often takes a toll on confidence. But routine investigations frequently fail to identify the cause.The study compared 44 women with hair loss to 30 without it. It found that levels of 3α-diol G—a marker of hormone activity within hair follicles—were nearly double in affected women, and higher levels were linked to more severe thinning.Explaining the distinction, Dr Kabir Sardana, Prof in dermatology department, RML Hospital said female pattern hair loss (FPHL) is a genetic, gradual thinning that often presents as a widening part, whereas telogen effluvium (TE) is a temporary, rapid shedding usually triggered by stress or illness. While FPHL leads to permanent miniaturisation of hair follicles, TE is typically self-limiting.He added, “We have always believed that female pattern hair loss is not due to androgens, but this is not true. It’s just that we have not been looking at the right place for the right test. We are already giving off-label anti-androgen drugs that inhibit these hormones, but they must be used with caution, especially in women who are planning pregnancy as they can affect conception.”Unlike conventional tests, 3α-diol G reflects hormone action at the level of the skin—where hair loss actually begins. This helps explain why many women continue to lose hair even when blood reports appear normal.Researchers also found that only a small fraction of patients showed abnormalities in routine hormone tests, pointing to limitations in current diagnostic approaches that rely on systemic measurements.Experts say the findings could shift the focus from hormone levels in blood to hormone activity in the scalp, potentially improving diagnosis and treatment. However, larger studies are needed before this approach becomes part of routine care.In simple terms, the study underlines a key message, researchers said that it is not just how much hormone is in the blood, but what it is doing at the hair follicle that determines hair loss.