Fish oil contains omega-3 fatty acids. Some studies suggest that omega-3s may improve hair health, particularly for people with hair loss. However, the evidence for this is currently limited.

A person can boost their intake of fish oil by changing their diet or taking supplements. Omega-3 supplements are also available.

It is worth keeping in mind that the contents and quality of supplements can vary greatly, and their labeling is not always accurate. Anyone interested in a supplement should research reputable brands and consider consulting a healthcare provider before making a purchase.

This article looks at whether fish oil is good for the hair and whether it can help with hair loss. It also explores recommended dosages and whether fish oil can cause side effects.

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Fish oil comes from various species of oily fish, such as herring, tuna, and mackerel. It is also available as a supplement, either as a liquid or in capsules.

Fish oil is rich in omega-3s, essential fatty acids that the body cannot make for itself. Two of the most well-known types of omega-3 are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

Companies can produce fish oil from any type of oily fish, so different products contain different types and quantities of omega-3s. Some may have little or no DHA or EPA.

Most research into fish oil has investigated the possible effects on hair loss. While these studies have been small, their results suggest that fish oil may promote hair growth.

The oil may have this effect by causing hair to enter its growth phase or stay there for longer.

Hair grows in four stages: anagen, catogen, telogen, and exogen, and the anagen stage is when growth happens. A 2018 study in animals found that fermented mackerel oil increased the amount of time that hair spent in the anagen phase. It is worth noting that this finding may not apply to humans.

However, a 2015 study with 120 female participants found that a supplement containing omega-3s and omega-6s reduced the amount of hair in the rest, or telogen, stage, and increased the amount in the growth stage.

Compared with a control group, the participants who had taken the supplement for 6 months reported less hair loss and more growth.

While this result seems promising, determining whether fish oil can reliably support hair growth in anyone will require further research.

Fish oil might help with thinning hair for the same reasons that it might help with hair loss. If hair spends more time in its growth stage, this might give a person the appearance of having more hair.

In addition, the 2015 study found that the supplement containing omega-3s and omega-6s led to greater hair diameter and density after 6 months, according to the reports of participants.

There is no official recommended daily dosage of EPA or DHA, as they are not essential nutrients. According to Harvard Health, a standard amount of EPA and DHA per day for an adult ranges from 250–500 milligrams (mg).

However, it can be difficult to judge the actual intake because the amounts in supplements vary — 1,000 mg of fish oil from one brand may contain less or more EPA and DHA than the same amount of oil from another brand.

People can get omega-3s from their diet. Oily fish is a good source of EPA and DHA. Few plant foods contain these types of omega-3, but algae oil is a suitable alternative for people with vegetarian or vegan diets.

A person who opts for a fish oil supplement may benefit from taking it with a meal that contains fat. Some evidence suggests that doing so can increase absorption.

Many people tolerate fish oil, and any side effects tend to be mild. The most common are:

Also, high doses of fish oil may prevent the blood from clotting correctly, posing a risk to people with certain bleeding disorders. These doses may also intensify the effects of anticlotting medication, such as warfarin (Coumadin).

Anyone with an ongoing health issue should speak with a doctor before trying a fish oil supplement.

Hair loss and thinning can be distressing and affect self-esteem. If a person notices unexplained hair loss, it may help to speak with a doctor.

Sometimes, hair loss results from hormonal changes caused by menopause or an underlying health condition, such as polycystic ovary syndrome (PCOS).

If a person has hair loss and any of the following symptoms, they should contact a healthcare provider:

  • irregular or no periods
  • unexplained weight gain
  • acne
  • oily skin or hair

A small amount of evidence suggests that fish oil containing substantial amounts of EPA and DHA may support hair growth.

However, determining whether fish oil can counter hair loss in humans will require more research.

Anyone thinking of trying fish oil for hair health should research reliable brands and contact a doctor if they have any ongoing health issues.