Breastfeeding and hair: what you can do and what to avoid

During breastfeeding, many mothers see their hair fall out in large amounts and, at the same time, have questions about what they can do: colour their hair, have highlights, a straightening treatment, use minoxidil, have PRP. The good news is that most care routines and several treatments are compatible with breastfeeding. There are few clear exceptions, and it is worth knowing them.

In this guide we explain, point by point, what the evidence says and how to decide safely.

What happens to hair during breastfeeding

Hair loss is not caused by breastfeeding itself

Hair loss that appears 2 to 4 months after birth is mainly due to the end of the hormonal changes of pregnancy. During pregnancy, more hairs stay in the growth phase; after birth, they all enter the resting phase at the same time and fall out weeks later. It is called postpartum telogen effluvium and it happens to those who breastfeed and those who do not. We explain the mechanism and timeline in Hair loss after childbirth: what is normal.

In a Japanese study, the duration of breastfeeding was associated with the intensity of hair loss (Hirose et al., 2023). This is an association in a questionnaire, not a demonstrated causal relationship, and it is no reason to stop breastfeeding.

What can weigh most during breastfeeding

• Lower iron reserves, because of pregnancy and blood loss at birth.
• Increased nutritional needs. Producing milk requires extra energy, protein and micronutrients.
• Fragmented sleep and tiredness, known triggers of effluvium.
• Thyroid changes. Postpartum thyroiditis affects about 5% to 10% of women and may appear during the breastfeeding period.
• Practical but tight hairstyles, such as tight ponytails and buns, which cause traction.

What if the hair loss reveals something else?

In some women, postpartum effluvium makes visible an androgenetic alopecia that was already starting. In a study of 200 women assessed at a consultation for postpartum hair loss, most also had signs of androgenetic or traction alopecia (Galal et al., 2024). It is in these cases that the question of treatments during breastfeeding arises.

How safety during breastfeeding is assessed

To work out whether a product or medicine is safe during breastfeeding, doctors ask three questions:

• How much passes into the mother's blood? Many products applied to the hair or scalp are absorbed in minimal amounts.
• How much of what is in the blood passes into the milk? It depends on the size of the molecule, how it binds to proteins and how long it stays in the body.
• Does the baby absorb what it receives? Some substances are poorly absorbed by the baby's gut.

There is also a fourth point, often forgotten: direct contact. The baby may touch the mother's hair or skin where the product was applied.

Doctors use specialist databases, such as LactMed, from the US National Library of Medicine, and e-lactancia, maintained by Spanish paediatricians, to look up the available information on each substance. In 2025, a review published in the International Journal of Dermatology brought together the evidence on treatments for hair loss during breastfeeding (Needle et al., 2025). The recommendations that follow are based on these sources.

A general principle: premature babies and newborns in the first weeks are more sensitive, because they eliminate substances more slowly. At this stage, more caution is needed.

Medical treatments for hair loss

Topical minoxidil: low risk, with one precaution

Minoxidil applied to the scalp is absorbed in small amounts: on average about 1.4% of the dose reaches the circulation. Passage into milk in relevant amounts is considered very unlikely, and e-lactancia classifies it as probably compatible.

The main concern is contact. Two cases of excess hair growth in babies have been described: one of 2 months whose mother applied 5% minoxidil twice a day, and another of 9 months who was carried on the shoulders of a grandfather who used the product. In both, the effect was temporary and disappeared in about 4 months.

In practice:

• apply at night, or when the baby is not in your arms;
• let it dry completely before picking up the baby;
• wash your hands well after applying;
• keep the baby's head and face away from the treated scalp;
• preferably foam, which runs less than a solution.

Low-dose oral minoxidil: a medical decision case by case

At the doses used for hypertension (7.5 to 10 mg a day), the amount passing into milk was considered clinically insignificant and no problems were observed in the baby. The doses used for hair loss are much lower, usually 0.5 to 2.5 mg a day. Even so, it is a medical decision, with more caution in premature babies and in the first weeks of life (Needle et al., 2025; e-lactancia).

Finasteride and dutasteride: avoid

Finasteride is not indicated in women and is contraindicated in women who are or may become pregnant, because of the risk of genital changes in a male foetus. It is not used during breastfeeding. The same applies to dutasteride.

Platelet-rich plasma (PRP): minimal risk

PRP uses the person's own plasma, injected into the scalp. It does not introduce medicines into the body, and the 2025 review considers the risk to the baby minimal (Needle et al., 2025). It is an option for those who do not want to or cannot use medicines. Its efficacy in androgenetic alopecia is supported by randomised trials, but protocols vary.

Low-level laser: safe

Helmets and low-level light combs involve no medicines and have no interactions, so they are considered safe during breastfeeding.

Ketoconazole 2% shampoo: safe

Useful when there is dandruff or seborrhoeic dermatitis, which can make scalp discomfort worse. Absorption is negligible.

Others

• Spironolactone: passes into milk only in traces and has not been associated with harm to the baby, but it is always prescribed and monitored by a doctor.
• JAK inhibitors (used in severe alopecia areata): they pass into milk, and breastfeeding is usually suspended during treatment.
• Corticosteroid injections into alopecia areata patches: they are localised and at a small dose; the decision is medical.

Hairdresser: colouring, highlights and straightening

Dyeing the hair

There are no specific studies on hair dyes during breastfeeding. What is known is that a healthy scalp absorbs only small amounts of dye, so very little reaches the blood and, even less, the milk (MotherToBaby, 2024).

To reduce exposure even further:

• use techniques that do not touch the scalp, such as foil highlights or balayage;
• do not apply if the scalp has wounds, irritation or eczema;
• colour in a well-ventilated space;
• respect the rest periods indicated;
• do the allergy test 48 hours beforehand, because skin sensitivity can change after birth.

Keratin straightening and "hair botox"

Here the recommendation is different. Many keratin-based straightening treatments contain formaldehyde or substances that release formaldehyde when heated by the iron. One study found products with up to 5.9% formaldehyde, including some labelled "formaldehyde-free" (Palmer and McMichael, 2024).

In the European Union, formaldehyde is classified as carcinogenic and sensitising and is banned as an ingredient in cosmetics. Some substances that release it are still permitted, and products must state "releases formaldehyde" on the label when the content exceeds 0.001%, a rule mandatory for all products on sale from 31 July 2026 (Regulation (EU) 2022/1181).

The main risk lies in the fumes inhaled during application and in the salon environment, which can also reach the baby if present. While breastfeeding, and especially in the first months, it is prudent to postpone these treatments. If you do have them, choose products proven to be free of formaldehyde and formaldehyde releasers, in a well-ventilated salon, and do not take the baby with you.

Perms and relaxers

They use strong chemicals, but with little absorption through healthy skin. The same rules: ventilation, a scalp without wounds and, if possible, waiting for postpartum hair loss to settle, because chemicals weaken the hairs and can increase breakage.

Diet and supplements during breastfeeding

Breastfeeding increases the need for energy and for several nutrients. When diet does not keep up, hair is one of the first things to show it.

Supplements: with discernment

• Keep taking the supplement recommended by your obstetrician or GP.
• Do not add "hair" supplements on your own. Many contain high doses of vitamin A, selenium or biotin. Excess vitamin A and selenium can even cause hair loss, and biotin interferes with thyroid tests, which are precisely among the most useful tests in the postpartum period.
• Iron only with blood tests. If ferritin is low, the doctor indicates the dose and duration.

More details in Iron and vitamins after birth and Diet and hair loss: what each strand needs.

Daily care routine

With a baby at home, time is short. These quick steps make a difference:

• Wash when you need to. Washing does not increase hair loss: it only releases hairs that were already going to fall. Use a gentle shampoo and conditioner on the ends only.
• Detangle carefully, from the bottom up, with a wide-toothed comb, preferably with the conditioner still applied.
• Dry without damage. Press with a towel, do not rub; hairdryer at a medium temperature and at some distance.
• Loose hairstyles. Prefer loose braids, claw clips or spiral hair ties to tight ponytails. It is also worthwhile because babies pull hair.
• Less heat. Cut down on straighteners and stylers while hair loss is active; weakened hair breaks more easily.
• A strategic cut. Shorter or layered hair gives more volume and disguises thinning while new hair grows.
• Satin or silk pillowcase. It reduces friction on restless nights.

To track progress, take a photograph of the top of the head and the parting every 3 months, always in the same light.

Summary: what you can do while breastfeeding

This table is a general guide. The decision on any medicine should be made with your doctor, taking into account the baby's age and health.

When to seek a medical assessment

Low mood, anxiety and persistent tiredness in the postpartum period deserve their own attention: talk to your GP or obstetrician.

At Luxmed, the Hair Medicine consultation assesses the cause of hair loss with trichoscopy and, when indicated, blood tests, and sets out a plan compatible with breastfeeding.

This article is for information only and does not replace follow-up with your doctor, obstetrician or paediatrician.

Frequently asked questions