If you have been reading about hair loss for more than ten minutes, you have already met DHT. It is the hormone blamed for almost everything, the one that turns a full head of hair into a thinning one.
And for a lot of people, DHT genuinely is the issue. But not for everyone. Since I started CLYNN, I have had the same conversation hundreds of times. Someone has tried every DHT blocker on the shelf, spent a lot of money, and nothing changed. Most of the time that is not because the products were bad. It is because they were solving the wrong problem.
DHT is real, but it is one cause among several
DHT (dihydrotestosterone) shrinks hair follicles over time. It causes the classic pattern: a receding hairline, a widening part, thinning at the crown. It is genetic, it is gradual, and it does not come and go based on how stressed you are that month.
That is the key detail. DHT loss is steady and directional. It follows a shape. If your hair is thinning evenly all over, or if you can point to a week when it suddenly started, you are probably looking at something else.
Here are the four things I see most often in Australia that get mistaken for DHT.
1. Low iron and ferritin
This is the big one, especially for women. Iron is needed to make hair. Not to make it grow faster, but to make it at all. When your stores are low, the body quietly deprioritises hair, because hair is not essential and your organs are.
Australian women are at real risk here. Iron deficiency is common, and it often sits just below the line where a GP would flag it. A ferritin of 20 can be called normal on a lab report and still be low enough to shed hair.
What it looks like: diffuse thinning across the whole scalp, more hair on the pillow and in the shower, often alongside tiredness, cold hands, or breathlessness on stairs. If that sounds familiar, ask for a ferritin test specifically, not just a standard iron study.
2. Thyroid trouble
Both an overactive and an underactive thyroid can push hair into the shedding phase. Underactive is far more common, and it turns up more often in women over 30.
It is sneaky because the hair change usually lags behind the thyroid change by a few months. You might start shedding in autumn for something that happened in winter. Typical companions are fatigue, weight changes, feeling cold all the time, or a cycle that has drifted.
A simple thyroid panel settles it. This is worth doing before you spend six months on a scalp routine that cannot possibly help.
3. Hard water and scalp buildup
A lot of Australia has mineral-heavy water. In Perth and parts of South Australia, water hardness is high enough that you can feel it on your hair.
Hard water does not directly cause hair loss. But it leaves calcium and magnesium deposits on the scalp, and those interfere with how well your scalp can shed dead skin and keep its barrier intact. Over time that shows up as itch, flaking, and a scalp that feels tight no matter how much you wash it. And an irritated scalp is a bad place to try to grow hair.
The fix is not a stronger shampoo. It is a gentler, chelating cleanse and a scalp that is not constantly inflamed. If your hair feels straw-like after washing and your shower head has white crust on it, this is worth looking at.
4. Diet and rapid weight change
Crash dieting, cutting protein, going hard on a low-calorie plan for a wedding, starting a GLP-1 medication: all of these put your body under stress. Hair gets pushed into its resting phase and falls out roughly two to three months later.
This kind of shedding is called telogen effluvium, and the important thing to know is that it is temporary. Once the stressor stops and your nutrition recovers, the hair grows back. It just takes a full growth cycle to show up, which is roughly three to six months.
What it looks like: a sudden increase in shedding, evenly spread. Not a patch. Not a receding line. Just more hair everywhere, all at once.
How to tell which one is yours
Here is the short version I give people.
- Patterned and slow: receding hairline, widening part, thinning crown. Likely DHT. This is where a DHT-focused routine makes sense.
- Sudden and even: started within the last few months, hair all over the head. Look for a trigger first. Stress, illness, diet, medication, iron, thyroid.
- Scalp-first: itch, flake, tightness, buildup, straw-like texture. Fix the scalp before anything else.
- Cyclical: comes and goes with life events. Postpartum, perimenopause, illness. Usually telogen effluvium.
If you tick more than one box, that is normal. Most people do. Fix the reversible ones first, because they are cheap to test and quick to correct.
What I would actually do first
Before buying another serum, spend the money on a blood test. Ferritin, full blood count, thyroid panel, vitamin D. It is the single highest-value thing you can do for your hair, and it tells you whether everything else is a waste of time.
If the tests come back clean and your thinning is patterned, then you are in DHT territory and a targeted routine makes sense. If the tests show a deficiency, fix that first and give it three to six months before judging anything.
And while you wait, treat your scalp well. A gentle, sulfate-free cleanse and a formula built around scalp health will not hurt, and it often helps more than people expect, because an inflamed scalp is a scalp that struggles to grow anything.
If you are not sure which category you fall into, our free hair analysis takes about two minutes and points you to the right starting point rather than the most expensive one.
If you already know your thinning is genetic and patterned, start here instead: CLYNN hair loss support, where the routines are built around scalp health and DHT.
This article is general information, not medical advice. Hair loss can be a sign of an underlying condition, so please see your GP for blood tests and a proper diagnosis.
