Thinning Hair: Why It Happens and What Actually Helps

If you have noticed your parting looks wider in photos, your ponytail feels thinner, or you’re finding more hair strands in the shower plug than usual. It’s understandable to feel worried or even anxious about your appearance, especially if you don’t know why it is happening, but thinning hair can affect women of all ages and may be more common than you realise.

Sometimes it follows a specific event, such as childbirth or illness. Sometimes the change is gradual and harder to explain. Either way, you deserve a better answer than “it’s probably stress”. 

Often, the first step in identifying a cause is figuring out what type of hair thinning you’re experiencing. This can help you decide whether to give your hair time to recover, change something that’s straining your body, or speak to a clinician about hair loss treatment. Here’s what to look out for and what can actually help.

What Is Thinning Hair? (And How Is It Different From Hair Loss?)

Thinning hair means hair that looks or feels less dense than it used to. Hair loss is a broader term that describes gradual thinning, increased shedding and distinct bald patches or a receding hairline.

Hair shedding is a normal part of your hair growth cycle, and most people lose 50 to 100 hairs per day without noticing.* You may notice more on a wash day because several days’ worth of loose hairs may come away at once. What matters more is a sustained change from your usual pattern.

If hair thinning is affecting you, possible signs include:

• Wider parting

• More visible scalp 

• Thinner or smaller ponytail

• Receding hairline

• Excessive shedding 

* NHS. (2024). Hair Loss.  

Common Causes of Thinning Hair in Women

Hair growth is slow and responds slowly to changes in the body, which is why a trigger may have happened months before you notice more hair falling out. A clinician will usually ask when the thinning began, where it’s happening, and what else was happening in your life around the time you noticed it. Several factors can cause hair thinning, including your lifestyle, genetic makeup, and underlying health conditions.

Hormonal changes

Hormonal fluctuations are a common reason for women to notice thinning hair. A common cause is pregnancy and labour. During pregnancy, hair often feels fuller, but after birth, hormonal changes can cause significant hair shedding around the same time, known as postpartum shedding. It usually occurs 2 to 4 months after birth, lasts 6 to 12 months, and is a type of diffuse alopecia that affects the whole scalp rather than specific patches.*

Perimenopause and menopause are also common hormonal causes of hair thinning in women, as hormone changes can make hair loss more noticeable. It usually happens gradually, affecting the crown or widening the parting,** and can even begin before your periods stop altogether. 

Polyendocrine metabolic ovarian syndrome (PMOS), formerly known as PCOS, is associated with an increased level of androgens – male hormones that can contribute to hair thinning. One clinic noted that out of 472 women diagnosed with female pattern hair loss, 8% had a PMOS diagnosis.*** Other potential symptoms of PMOS include irregular periods, acne, or increased facial hair, which may help to narrow down the cause of a sparser-looking scalp. 

Thyroid conditions, like an underactive thyroid, can cause dry, thinning hair or loss, often alongside symptoms such as tiredness and feeling cold. Some people also notice increased shedding after starting or changing hormonal contraception.

* Hirose, A. et al. (2023). Investigation of exacerbating factors for postpartum hair loss: a questionnaire-based cross-sectional study.

** Rinaldi, F. et al. (2023). The Menopausal Transition: Is the Hair Follicle “Going through Menopause”?

*** Prasad, S. et al. (2020). Polycystic ovarian syndrome in patients with hair thinning.

Stress and lifestyle

When your body is under increased physical or emotional strain, it can push more hairs than usual into the resting phase of the hair cycle. The resulting shedding is a condition called telogen effluvium and can happen following an illness, surgery, childbirth, major stress, rapid weight loss or crash dieting or inadequate nutrition. Because shedding can occur a few months after the initial trigger, the connection isn’t always obvious at first.*

However, this doesn’t mean that every case of thinning can be cured by simply learning to relax more. That advice misses the point when someone is dealing with a nutrient deficiency, an underlying condition or female pattern hair loss. 

Like the rest of your body, your hair needs energy, protein, and the right nutrients to grow. Restrictive diets leave you short of what you need, leaving you at a higher risk of conditions, such as iron deficiency, which can also cause hair loss, especially if you also have heavy periods. If you’ve recently lost a lot of weight rapidly or changed your diet, these could also be contributing to increased shedding and the onset of telogen effluvium. Being open with your clinician about any changes to your health or lifestyle will help them determine the next steps. 

* British Association of Dermatologists. (2025). Telogen effluvium. 

Styling and tension

Even how you style your hair can cause thinning. For example, a tight hairstyle can repeatedly strain your hair follicles. Thinning at the temples or along your hairline may signal traction alopecia, especially if you wear tight braids, extensions, or pulled-back styles. Reducing tension early gives your hair a better chance to recover, while prolonged traction can lead to lasting hair loss.*

That’s not all. Heat tools, bleaching, and rough handling can also break hairs at the shaft, making your hair look thinner even though your follicles are still producing hair. Take a look at the hairs that are falling out. If you see lots of shorter, snapped pieces, that could signal damage, while full-length hairs shed from the root could signal hair loss. You may also have evidence of both.

* British Association of Dermatologists. (2025). Traction alopecia. 

Underlying health conditions

Sometimes hair thinning signals something else that needs medical attention. Iron deficiency and thyroid problems are common examples, while autoimmune conditions can also be responsible. Scalp inflammation can also damage hair follicles, so getting a prompt diagnosis is important, especially if your scalp is painful or appears red or different to what you are used to. 

You’re not alone, and there’s no need to identify the cause of your thinning hair on your own. If the change is sudden, significant, or worrying, book an appointment with your doctor. 

Treatments Proven To Help With Thinning Hair

The right treatment for thinning hair depends on the cause. A product intended for female pattern hair loss won’t correct an iron deficiency, and a supplement won’t relieve tension from a tight hairstyle. At first, it can help to analyse your lifestyle to identify potential triggers, note the pattern of loss and set realistic expectations for recovery. 

Topical minoxidil

Topical minoxidil is an established treatment for female pattern hair loss. It’s applied to the scalp as a solution or foam and is available over the counter in 2% and 5% concentrations. Generic topical minoxidil and branded alternatives, such as Regaine, are available, but follow the instructions for the specific product you choose. Minoxidil can help slow thinning and encourage some regrowth, but it may not work for everyone.

Minoxidil works by increasing blood flow, oxygen and nutrient delivery to the scalp to help reduce hair shedding. It helps to shorten the resting phase of the hair growth cycle and pushes dormant follicles back into active growth. Research also suggests that minoxidil lengthens the growth phase of the hair cycle, so that your hair grows longer and thicker.*

You may notice improvement after several months of using topical minoxidil, usually 3 to 6 months, but consistent use matters for the best results.

* Messenger, A. G. et al. (2004). Minoxidil: mechanisms of action on hair growth.

Prescription options

If topical treatment isn’t suitable or hasn’t helped enough, a clinician may discuss other options after assessing your health and the type of hair loss.

Spironolactone

Spironolactone reduces the effects of androgens and is sometimes prescribed off-label for female pattern hair loss. “Off-label” means the medication is being used for a purpose outside its UK licence. It isn’t right for everyone, and your clinician will need to review your current health and other medications you are taking. Hair changes are gradual, so treatment is usually assessed over months rather than weeks. 

Low-dose oral minoxidil

Low-dose oral minoxidil is another off-label option used by some specialists and is thought to work similarly to topical minoxidil by increasing blood flow to your hair follicles.* Its evidence and safety considerations differ from those of topical minoxidil. Because it can affect blood pressure and cause other side effects, it requires individual assessment and appropriate monitoring. It’s not a tablet to start simply because a scalp product feels inconvenient. 

Prescription treatment isn’t the answer to every type of thinning. Someone with telogen effluvium may need help identifying and addressing the trigger, while someone with a scalp condition may need treatment directed at inflammation. That’s why getting the diagnosis right matters.

* NHS Northern Care Alliance. (2025). Dermatology - Low dose minoxidil for hair loss.

Supplements

Supplements for hair loss can help if you have a nutrient deficiency. If tests show iron deficiency, for example, treating it addresses a possible contributor to hair loss as well as the deficiency itself. A clinician may recommend other tests based on your diet, symptoms and medical history. Taking iron without knowing whether you need it can cause side effects and may delay finding the real cause.

If blood tests show you are low in several nutrients, such as zinc, folic acid, and B vitamins, a clinician may recommend a daily multivitamin, while some people opt for a biotin supplement because of its reported hair benefits. However, if you already eat a healthy, balanced diet, you likely don't have a nutrient deficiency, and taking more vitamins and minerals than you need probably won't help.*

* Patel, D. P. et al. (2017). A Review of the Use of Biotin for Hair Loss.

Lifestyle adjustments

Small lifestyle changes can be enough to protect your hair, whether thinning is caused by an underlying condition or not. From following a healthy diet to managing stress, several factors can affect your hair, and a few small adjustments can help restore its health and appearance. 

Some of the things you can do to protect your hair include:

• Eat a balanced diet that includes good protein sources and iron, as well as a variety of natural foods, such as fruit, vegetables and whole grains, to ensure you’re getting all the nutrients your body needs.

• Lose weight gradually if you are on a weight loss plan. Losing weight too quickly, even on weight loss medications, can cause telogen effluvium and temporary hair loss. Aim to lose 0.5 to 1kg per week for safe and sustainable weight loss.*

• Quit smoking if you’re a smoker because research shows it can negatively affect the hair growth cycle and even strip your hair of its natural colour.**

• Reduce stress by practising meditation, mindfulness, or finding a hobby you enjoy to help keep stress hormones, like cortisol, within a healthy range.

• Handle hair gently by reducing excessive heat, avoiding harsh brushing and relaxing tight hairstyles. 

* NHS Inform. (2026). Tips for losing weight safely.

** Babadjouni, A. et al. (2021). The Effects of Smoking on Hair Health: A Systematic Review.

When to See a Doctor About Thinning Hair

Gradual thinning is common, and it usually isn’t an emergency, but you don’t need to wait for a bald patch to appear before asking for help. A clinician can review your symptoms, examine your scalp and arrange for further tests where appropriate. If you’d like to explore treatment for gradual thinning, an online hair consultation may also be a convenient first step.

Speak to a doctor if you notice:

• Sudden or rapid hair loss, or clearly defined bald patches

• Pain, burning, marked itching, redness or scaling on the scalp

• Thinning alongside fatigue, weight changes, heavy periods or changes in your menstrual cycle

• Hair loss that continues or worsens after childbirth, illness or a major change in diet

• Thinning at the temples or hairline that may be related to repeated tension

• Hair loss that is affecting how you feel, even if it looks mild to someone else

A clinician may ask about recent illness, pregnancy, medications, diet and family history. For widespread thinning, blood tests may help check for causes such as low iron stores or a thyroid problem. If the scalp looks inflamed, or the diagnosis is unclear, you may need a dermatology assessment.

If you have noticed gradual thinning and want to discuss treatment, explore Hers UK’s hair loss service. A Hers clinician can review your health history and determine whether a treatment such as topical minoxidil is appropriate for you.