Hair and Nail Changes in Pregnancy

What is actually happening

Hair grows in cycles: a long growing phase, a short transition, then a shedding phase. Ordinarily you lose a slice of it continuously — the NHS puts normal loss at 50 to 100 hairs a day, which is why you never notice.

Pregnancy tilts that balance. ACOG puts it simply: "The hormone changes in pregnancy may cause the hair on your head and body to grow or become thicker." The NHS lists "thicker and shinier hair" among ordinary second-trimester changes. Nothing has actually been added — you are just shedding less of what you already had.

ACOG also notes a less-advertised version of the same effect: "Sometimes women grow hair in areas where they do not normally have hair, such as the face, chest, abdomen, and arms." That resolves too. ACOG's timeline for hair returning to normal is "within 6 months after giving birth".

Nails

Nail changes get almost no coverage, so here is what ACOG says in full: "Some women find that their nails grow faster during pregnancy. Others notice that their nails split and break more easily. Like the changes to your hair, changes that affect your nails will ease after birth."

That is genuinely the extent of the guidance. Faster growth and more splitting are both described, they point in opposite directions, and both are normal. There is no recommended treatment, and no evidence-based supplement to take for it. Keeping nails shorter while they are brittle is practical advice, not medicine.

The postnatal shed

This is the change that alarms people, and it is the most predictable one on the page.

The HSE names it: "Hair loss after giving birth is called telogen effluvium." The mechanism is the pregnancy effect running in reverse — "the rapid change in hormone levels causes your hair to move from the growth phase to the shedding phase". All the hair you did not shed during pregnancy leaves at roughly the same time.

The timing is consistent. ACOG: "About 3 months after childbirth, most women begin to notice hair loss from the scalp... In most cases, your hair should grow back completely within 3 to 6 months." The HSE agrees: "Telogen effluvium usually resolves after 3 to 6 months. This is the normal length of the shedding phase before the growth phase begins again."

What it looks like, per the HSE: more hair coming out when you brush, hair in the shower drain, on your pillow and around the house. It usually thins across the whole scalp, though some people notice more obvious loss in particular patches.

What is not normal

Most postnatal shedding needs nothing at all. The things worth a GP appointment are:

• Hair loss that is still getting worse beyond about six months.
• Distinct bald patches rather than general thinning.
• Hair loss with other symptoms — exhaustion, breathlessness, feeling cold, low mood — because the HSE specifically suggests blood tests to check iron and thyroid levels.
• Hair loss you are simply worried about. The NHS's threshold for seeing a GP is exactly that: "if you're worried about your hair loss", and it advises seeing a doctor to find the cause before paying a commercial hair clinic.

The NHS also lists causes of temporary hair loss unrelated to pregnancy that are worth ruling out: illness, stress, weight loss and iron deficiency.

One caution: the NHS pages on treating hair loss discuss medicines such as finasteride and minoxidil in a general context, and note they "only work for as long as they're used". Do not start any hair-loss medicine while pregnant or breastfeeding without checking with your midwife or doctor first.

What actually helps

For the shedding: mostly time

The HSE's position is that no treatment is usually needed. Its practical suggestions are a good diet containing iron, protein, fruit and vegetables, stopping smoking, blood tests for iron and thyroid if appropriate, and vitamin supplements designed for postnatal or breastfeeding women.

Notice what is absent: no shampoo, serum or supplement is recommended as a treatment for telogen effluvium. That is not an oversight — it reflects the fact that the hair is coming back on its own schedule regardless.

Hair removal

ACOG says it is "safe to use tweezing, waxing, and shaving to remove unwanted hair during pregnancy".

Hair dye

The most common question, and the NHS answer is reassuring: "Most research shows that it's safe to dye or colour your hair while pregnant." The reasoning is exposure — the chemicals involved are only harmful in very high doses, and very little is absorbed through the scalp.

The NHS adds practical precautions: some people choose to wait until after the first 12 weeks, and if you are colouring at home you should "wear gloves, as skin can be more easily irritated while you're pregnant", work in a well-ventilated room, leave the dye on for the minimum time in the instructions, and rinse thoroughly. It also notes lower-exposure options — highlights, which touch only the hair strands rather than the scalp, and semi-permanent vegetable dyes such as henna.

The short version

Thicker hair and faster or more brittle nails are normal and temporary. The shed at three months after birth is telogen effluvium and is usually over by six months. See a GP for patchy loss, loss that keeps worsening past six months, or loss with other symptoms — and ask for iron and thyroid checks, which is the one useful test on this page.