Hair Loss, Thinning and Shedding: What Your Thyroid and Hormones Might Be Telling You
If you’ve noticed more hair than usual in the shower drain or on your pillow lately, you’re not alone — hair shedding tends to spike in winter, and it’s one of the most emotionally difficult symptoms women bring to a naturopath. While some seasonal shedding is completely normal, hair that’s noticeably thinning, falling out in handfuls, or not growing back is usually your body signalling that something hormonal is off — most often involving your thyroid, your iron levels, or a broader hormonal shift.
Below, I’ll walk through the three most common hormonal and thyroid causes of hair loss I see in clinic, what standard blood tests tend to miss, and what naturopathic treatment can actually look like.
The Three Most Common Hormonal and Thyroid Causes of Hair Loss in Women
Hair follicles are incredibly sensitive to shifts in hormones and nutrient levels, which is why hair loss is often one of the earliest visible signs that something deeper needs attention.
Thyroid dysfunction
Both an underactive and an overactive thyroid can cause diffuse hair thinning across the whole scalp, rather than in one particular patch. Thyroid hormone plays a direct role in the hair growth cycle, and when levels are off, more hairs than usual shift into the shedding phase at once. I’ve written about the wider picture of thyroid-related hair loss, along with the cold intolerance and fatigue that often come with it, in Why You’re Always Cold, Tired and Losing Hair - and What Your Thyroid Might Be Trying to Tell You.
Low iron and nutrient deficiencies
Iron, along with zinc, vitamin D and adequate protein, is essential for healthy hair follicles. Low ferritin is one of the most common — and most overlooked — contributors to hair shedding in women, especially those with heavier periods or plant-based diets. Because hair loss from low iron typically appears three to six months after levels drop, it’s easy to miss the connection.
Hormonal shifts
Hormonal hair loss isn’t limited to menopause. Coming off the pill, postpartum hormone shifts, and the oestrogen and androgen changes of perimenopause can all trigger noticeable shedding. If you’re also noticing other perimenopausal changes, it’s worth reading Perimenopause at 40? The Early Signs Most Women Miss.
What Standard Blood Tests Often Miss
A “normal” TSH result doesn’t rule out a thyroid contribution to hair loss, particularly if Free T3, Free T4 and thyroid antibodies were never checked. The same goes for iron — a normal haemoglobin doesn’t mean your ferritin is at a level that supports healthy hair growth. I go into this gap in more detail in Hypothyroidism: What You Need to Know If Your Results Keep Coming Back Normal.
What Functional Testing Can Reveal
In clinic, I usually look at a full thyroid panel with antibodies, complete iron studies, zinc, vitamin D and sometimes a hormone panel, depending on your cycle and symptoms. This gives a much clearer picture of what’s actually driving the shedding, rather than guessing based on a single “normal” result.
What Naturopathic Treatment for Hair Loss Looks Like
Treatment depends entirely on what testing reveals. It might mean correcting an iron deficiency, supporting thyroid function nutritionally, or addressing the hormonal shifts of perimenopause. Diet also plays a role — the nutrients that support thyroid health are covered in The Best Foods to Eat for Thyroid Health (And What to Cut Back On). Because hair growth cycles are slow, most women need three to six months of consistent support before seeing visible regrowth, so patience — and the right testing from the start — really matters.
Frequently Asked Questions
Why is my hair falling out even though my thyroid results are normal?
Standard testing often only checks TSH, which can miss thyroid dysfunction that’s still affecting your hair follicles. A full thyroid panel with antibodies gives a much more complete picture.
Can low iron cause hair loss?
Yes. Low ferritin is one of the most common causes of diffuse hair shedding in women, and it can occur well before you become clinically anaemic.
Will my hair grow back once the cause is treated?
In most cases, yes, though regrowth is gradual. Hair grows in cycles, so it typically takes several months of consistent treatment before you notice a visible difference.
How long does hormonal hair loss take to improve?
Most women notice reduced shedding within three to four months of addressing the underlying cause, with visible regrowth following over the next six to twelve months.
Hair shedding often overlaps with other symptoms like fatigue — if that sounds familiar, it’s worth reading Why Am I So Tired Even When I Sleep Enough? A Naturopath Explains as well.
If your hair loss has been bothering you and you’re not sure where to start, book a free introductory call and we’ll talk through what testing might help explain what’s going on.