Not all hair loss is the same, and the first job is to work out which kind you are dealing with. Each type leaves a distinctive signature in how, where and when the hair goes, and two clues, the pattern and the timing, sort most of them. Here is how to tell the common hair fall types apart, and which ones a cosmetic can support versus which belong to a doctor.
The main types at a glance
Sort them by pattern (diffuse all over, a defined area, or scattered patches) and by timing (sudden versus gradual, and whether anything happened a few months earlier).
- Telogen effluvium: sudden, heavy, all-over shedding, two to three months after a trigger.
- Androgenetic alopecia: slow thinning in a pattern, at the crown, temples or along the parting.
- Alopecia areata: sudden, smooth, round bald patches.
- Traction alopecia: thinning where the hair is pulled tight, at the hairline and edges.
- Breakage: not true loss at all, but hair snapping along its length.
Telogen effluvium: diffuse shedding after a trigger
This is the "my hair is falling out in handfuls" picture: general thinning all over the scalp rather than in one area, most obvious in the shower or on the brush. The hallmark is timing. A stressor, an illness or high fever, surgery, crash dieting, a thyroid change or childbirth pushes many follicles into the resting phase at once, and they shed together two to three months later. The follicles are not damaged, so telogen effluvium recovers on its own once the trigger passes. Postpartum shedding is the most common version; our guide to postpartum hair loss covers the timeline and what helps.
Androgenetic alopecia: gradual pattern thinning
Where telogen effluvium is sudden and diffuse, androgenetic alopecia, the hereditary kind, is slow and patterned. Density fades over years rather than weeks, along a fixed map: a receding hairline and crown in men, a widening parting or general thinning across the top in women with the front hairline preserved. Follicles sensitive to dihydrotestosterone (DHT) shrink with each cycle, so hairs grow back finer and shorter. Our guide to what happens inside the follicle sets out the mechanism in full.
This is the one type where a botanical active has a measured receipt for density, and density is the peptide. In a 24-week, independent, triple-blind randomised trial of 32 people with androgenetic alopecia, 16 men and 16 women, a tonic combining biochanin A, acetyl-tetrapeptide-3 and ginseng raised terminal hair count 8.3%, against 8.7% for 3% minoxidil, with no statistically significant difference between the two arms (Lueangarun & Panchaprateep, J Clin Aesthet Dermatol 2020). The load-bearing molecule is biochanin A, a red-clover isoflavone that inhibits the type-2 isoform of 5-alpha-reductase, the enzyme that makes DHT in the scalp follicle (Hiipakka et al., Biochem Pharmacol 2002). It is one trial of 32 people, and non-significance is not proven equivalence, so it is a strong signal, not a final verdict. That biochanin-A and acetyl-tetrapeptide-3 load is what carries density in Tara's red onion and peptide collection: the onion is the identity botanical, the peptide is the density active. Separately, rosemary oil matched 2% minoxidil on hair count over six months in a randomised trial of 100 men with the condition, with less scalp itching (Panahi et al., Skinmed 2015), and it anchors Tara's rosemary and peptide range.
Alopecia areata: sudden round patches
Alopecia areata is the odd one out. Instead of diffuse thinning you get one or more smooth, round, coin-sized bald patches that appear suddenly, with normal-looking skin and no scaling. It is autoimmune: the immune system temporarily attacks specific follicles. A cosmetic does not treat it. No shampoo or serum addresses an autoimmune process, the hair often regrows on its own, and medical treatments exist, so this one is diagnosed and managed by a doctor.
Traction alopecia and breakage: damage, not disease
The last two are mechanical stress, not the follicle cycle. Traction alopecia comes from hair pulled tight, repeatedly, by braids, tight ponytails, buns or extensions, and the thinning shows up exactly where the tension is greatest: the hairline and the edges around the temples. Caught early it improves once you loosen the styling; left for years the follicles scar and the loss becomes permanent.
Breakage is often mistaken for hair loss but is different: the hair snaps partway along the strand instead of shedding from the root. The tell is short, broken hairs of varying lengths, split ends, and a frizzy, uneven feel, from heat, bleaching, over-styling or rough handling. The follicle is fine; the fibre is damaged. Gentle handling, less heat and a strengthening routine fix it, and the hair loss hub sets out the wider picture.
When medical care is the right next step
Cosmetic routines support scalp condition, density appearance and the follicle environment. Smooth round patches, sudden patchy loss, rapid shedding, redness, scaling, pain or scarring need diagnosis first because those patterns can come from medical causes such as autoimmune alopecia areata. A scalp routine can sit beside the right plan, but the pattern should be identified by a doctor.
One piece of internet folklore needs retiring too. The widely shared figure in which roughly 87% of people regrew hair is alopecia-areata-only: crude onion juice at close to full strength, applied to that autoimmune disease over a few weeks (Sharquie & Al-Obaidi, J Dermatol 2002). It is a different disease from general thinning, and the juice sat orders of magnitude above the bulb extract in any cosmetic, so the percentage does not transfer to androgenetic alopecia, to telogen effluvium, or to a finished product. Onion is a scalp botanical; where a formula has measured density support, the receipt belongs to the peptides, not to the 87% figure. And even the peptide and rosemary trials are maintenance and modest regain over months, by design, in androgenetic alopecia, not a cure and nothing for non-androgenetic shedding.
When a doctor is the answer
A short bout of seasonal or post-stress shedding is rarely cause for alarm. See a doctor for loss that is sudden and patchy, for smooth round bald spots, for redness, scaling, pain or scarring, or for heavy shedding that does not settle after a few months, since hair loss can also flag thyroid issues or iron deficiency, and the right diagnosis is the foundation for the right plan.
Frequently asked questions
What are the main types of hair loss?
The most common are telogen effluvium (diffuse shedding after a trigger), androgenetic alopecia (gradual hereditary pattern thinning), alopecia areata (sudden round patches), traction alopecia (from tight styling) and breakage (hair snapping along its length rather than true loss). They differ mainly in pattern and timing.
How do I know which type of hair loss I have?
Read the pattern and the timing. Sudden all-over shedding two to three months after a stressor is telogen effluvium; slow thinning at the crown, temples or parting is androgenetic alopecia; smooth round bald patches are alopecia areata; loss at the hairline from tight styles is traction; and short, broken hairs of mixed lengths are breakage, not loss.
Which types of hair loss need a doctor?
Any sudden, patchy or rapid loss, smooth round bald spots, and redness, scaling, pain or scarring point to a medical cause a cosmetic cannot treat. Heavy shedding that does not settle after a few months, and a check for thyroid or iron-related causes, are also worth a visit.
Does onion regrow hair for thinning?
No. The often-quoted 87% regrowth figure is alopecia-areata-only: crude onion juice applied to that autoimmune condition at a strength far above any cosmetic extract (Sharquie & Al-Obaidi, J Dermatol 2002). It does not transfer to general thinning or to a finished product. In a formula, the measured density support comes from peptides such as biochanin A, not from onion, which is a scalp botanical.
Is there any proven topical for pattern thinning?
For androgenetic alopecia, yes, within limits. A biochanin-A, acetyl-tetrapeptide-3 and ginseng tonic raised terminal hair count 8.3% versus 8.7% for 3% minoxidil over 24 weeks, with no significant difference, in an independent triple-blind trial of 32 people (Lueangarun & Panchaprateep, J Clin Aesthet Dermatol 2020); rosemary oil matched 2% minoxidil over six months in 100 men with the condition (Panahi et al., Skinmed 2015). Both are maintenance and modest regain, not a cure.
Will hair grow back after telogen effluvium?
Usually, yes. In telogen effluvium the follicles are not damaged, just temporarily pushed into the resting phase, so once the trigger passes the shedding settles and regrowth follows over several months. A gentle, scalp-first routine supports that regrowth.
