What Promotes Hair Growth?

The growth of your hair is a complex, multifaceted process that’s controlled by several factors, from your genetics to your hormones, habits and even certain aspects of your diet. 

If you’re starting to lose your hair, or if you’ve simply noticed a few extra strands of hair on your pillow or elsewhere around the house, you may have wondered if there’s anything that you can do to promote and maintain healthy hair growth.

While certain aspects of the hair growth process are outside of your control, there are several steps that you can take to promote hair growth.

These include eating the right foods, maintaining a healthy lifestyle, avoiding certain drugs and hair-unfriendly substances and, if necessary, using medication to prevent damage to your hair from the hormonal factors that cause hair loss.

Below, we’ve explained the factors that promote hair growth, as well as what you can do to use them to your advantage for a healthy, long-lasting head of hair.  

Hair Growth: The Basics

  • Your hair grows as part of a complex, multi-phase cycle that goes from growth to rest, shedding, and replacement.

  • Throughout this cycle, your hair depends on a steady supply of nutrients to grow to its full length and remain healthy.

  • While no foods are scientifically proven to stop male pattern baldness, some foods are rich in nutrients that can help your hair stay thick and healthy.

  • Good habits, such as staying active and avoiding things that can damage your hair, can also promote healthy hair growth.

  • Several medications can improve your hair growth, including FDA-approved treatments such as minoxidil and finasteride. 

How Hair Growth Works

While hair growth looks simple from the outside, behind the scenes your hair follicles work on a constant basis to produce and grow new hairs. 

Your hair grows as part of a continuous, four-phase cycle that involves phases of active growth and inactivity. The different phases of the hair growth cycle are as follows:

The anagen phase

Often referred to as the growth phase of the hair cycle, the anagen phase is when new hair advances from the hair follicle and grows to its full length.

The length of the anagen phase can vary depending on the location of each hair follicle on your body. Hairs on your scalp generally have a long anagen phase that lasts for two to six years, while body hair has a shorter anagen phase of only a few months.

On average, about 85 percent to 90 percent of your hairs are in the anagen phase of the growth cycle at any one time.


The catagen phase

The catagen phase, or regression phase, is an intermediate phase that occurs between growth and shedding. In this phase of the hair cycle, the hair shaft detaches from the follicle and stops actively growing.

Although your hair detaches from its source of growth during this phase, hairs generally don’t shed during the catagen phase. Instead, this is simply the first phase in each hair’s transition from active growth to rest and shedding.

The telogen phase

The telogen phase, or resting phase, occurs near the end of each hair’s growth cycle. During this phase, the hair enters into a resting state with no active growth or change.

Like other phases of the hair growth cycle, the telogen phase varies in length based on where hair is located on your body. On average, around 10 to 15 percent of your hair is in the telogen phase at any time.

The exogen phase

The exogen, or shedding phase, occurs right at the end of the hair growth cycle. In this phase, the hair shaft is physically released from your scalp and the hair falls out, often while you’re washing, brushing or physically touching your hair.

On average, about 50 to 100 of your hairs are shed every day as part of the hair growth cycle. These hairs are replaced by new hairs in the anagen phase that, over the course of several years, go through the same growth, regression, rest and shedding process. 

When your body is supplied with the nutrients it needs for optimal hair growth, this cycle works smoothly in the background, allowing you to effortlessly maintain a full head of hair. 

However, a variety of things can interrupt the hair growth cycle, potentially causing everything from mild shedding to permanent hair loss. These include:

  • Nutrient deficiencies
  • Diseases and medical conditions
  • Physical injuries that affect your scalp
  • Psychological issues, such as stress or a traumatic experience
  • Hormones, such as dihydrotestosterone (DHT)

Most things that promote hair growth, whether they’re foods, medications or habits, function by either stopping damage to your hair or providing it with the nutrients it needs to optimally enter and complete its growth cycle. 

Medications to Treat Hair Loss

If you’re beginning to notice hair loss, several medications are available to shield your hair from damage and supply it with the nutrients it needs to grow to its full potential.

One of these medications, minoxidil, works by stimulating the growth of your existing hairs. The other, finasteride, protects your hair from the damage caused by the hormone DHT.

Minoxidil

Minoxidil is a topical medication. It comes as a liquid or foam and is designed for direct use on the areas of your scalp with noticeable hair loss. 

When minoxidil is applied to your scalp, it shortens the telogen (resting) phase of the hair cycle and encourages your hairs to enter into the anagen (growth) phase early.

Researchers don’t know exactly why minoxidil stimulates hair growth. However, most research suggests that it acts on the potassium channels of your vascular muscles and hair follicles -- a factor that may stimulate blood circulation and improve the supply of nutrients to your hair.

Minoxidil usually produces noticeable results after around two months, with the most significant results usually visible after four months of regular use.

Unlike other hair loss treatments, minoxidil is available over the counter, making it a convenient, easy-to-purchase option if you have started to notice shedding or other signs of hair loss. 

We offer minoxidil online, either on its own or as part of our Non-Prescription Hair Loss Kit. You can learn more about how minoxidil works to promote hair growth on its own and in combination with other treatments in our minoxidil vs. finasteride guide. 

Finasteride

Finasteride is an oral medication. It works by preventing your body from converting testosterone into dihydrotestosterone, or DHT.

As we’ve explained in our guide to DHT and hair loss, DHT is the primary hormone responsible for male pattern baldness. If you’re genetically sensitive to DHT, the small amount of DHT that’s produced by your body can have a serious negative impact on your hair over the long term.

Research shows that finasteride can lower serum DHT levels by more than 70 percent, helping to reduce the effects of DHT on your hair follicles.

By blocking the conversion of testosterone to DHT, finasteride stops hair loss from worsening. In some cases, it may even help you to regrow hair in areas of your scalp with thinning. It generally takes six months before the results of finasteride on hair growth are apparent. 

We offer finasteride online, following a consultation with a healthcare provider who will determine if a prescription is appropriate. You can learn more about how finasteride works, its results and more in our detailed guide to using finasteride for hair loss.

Hair Care Products

Some hair care products, including hair loss prevention shampoos containing active ingredients such as ketoconazole and saw palmetto, may help to prevent hair loss and stimulate the growth of your hair:

  • Saw palmetto shampoo. Saw palmetto is a herbal ingredient that’s used in many hair care products and shampoos, including our Thick Fix Shampoo.

    Some research shows that saw palmetto may reduce hair loss. For example, a study published in the Australasian Journal of Dermatology in 2015 found that topical use of saw palmetto caused an increase in hair growth over the course of 24 weeks.

    Our guide to saw palmetto and hair loss goes into more detail on the research behind saw palmetto as a natural hair loss treatment.

  • Ketoconazole shampoo. Ketoconazole, an antifungal medication, has been linked to improvements in hair growth in some research. For example, a 2020 review of available literature found that ketoconazole shampoo was “a promising adjunctive or alternative therapy” in the treatment of androgenetic alopecia.

    Our guide to ketoconazole shampoo and hair loss goes into more detail on the research behind ketoconazole and hair loss, as well as ketoconazole’s potential benefits for other skin and hair issues. 

Hair Loss Supplements

Several health supplements have been linked to hair growth. While the research behind these is much less comprehensive than it is for science-based medications like minoxidil and finasteride, some may offer real benefits for hair growth.

Vitamin, mineral and nutrient supplements linked to hair growth and hair loss prevention include:

  • Biotin. Biotin, or vitamin B7, is a B vitamin that plays a role in hair growth. While it can’t and won’t treat hair loss from male pattern baldness, taking a biotin supplement may be helpful for hair growth if you have a biotin deficiency, which is rare.

    Our Biotin Gummy Vitamins make it easy to add biotin to your hair care routine. You can learn more about how biotin works, its potential benefits and more in our complete guide to biotin for hair loss.

  • Other vitamins. In addition to biotin, several other vitamins each play roles in your hair growth cycle. We’ve talked about these more in our detailed guide to essential vitamins for a healthy head of hair.

  • Essential oils. In general, the evidence connecting essential oils to hair growth is mixed when it comes to reliability. In general, most studies of essential oils and hair are short in length, small in scale and far from comprehensive.

    With this said, a few studies have shown that some essential oils may offer benefits for hair growth and general hair health. Among these are rosemary oil, peppermint oil and tea tree oil.

Foods

Before we get into the specifics of food and hair growth, let’s clear one thing up. If you’re losing your hair due to male pattern baldness, changing your diet won’t prevent the harmful effects of DHT on your hair follicles.

However, adding certain foods to your diet may help to supply your hair with important nutrients for optimal growth, strength and thickness.

Numerous different foods contain important vitamins, minerals and nutrients for sustainable hair growth. These include:

  • Eggs. Eggs are an excellent source of protein, which is essential for creating your hair and the tissue of your body. They’re also rich in biotin -- a B vitamin that’s closely linked to hair growth.

  • Spinach and other leafy vegetables. Spinach and other green, leafy vegetables offer several nutrients that are linked to hair growth. One of these is iron, which can be found in abundance in a typical serving of spinach.

    Although iron doesn’t cause hair growth directly, research shows that men with pattern hair loss often have low iron levels.

  • Berries and other vitamin-rich fruits. Berries and other fruits are a fantastic source of vitamin C -- one of several vitamins that plays a role in producing collagen for your nails, skin and hair.

    Vitamin C is also important for proper iron absorption, which is important to prevent iron deficiency hair loss.

  • Salmon, mackerel and other fatty fish. Salmon, mackerel, tuna, sardines and several other types of fatty fish are excellent sources of omega-3 fatty acids.

    In addition to improving cardiovascular health, some research has found that omega-3s may be related to hair health. For example, a 2015 study found that women who took an omega-3 and omega-6 supplement experienced improvements in hair density.

  • Beef, lamb and other lean meat. Beef, lamb and other types of meat contain a large amount of protein -- an essential building block for your hair. When you don’t consume enough protein, due to crash diets or malnutrition, it’s possible to experience a temporary form of hair loss.

    In addition to protein, moderate consumption of red meat  is a great source of iron for both hair health and general wellbeing.

  • Beans, soybeans, nuts and seeds. Beans, soybeans, nuts and seeds are all sources of nutrients that your body needs to grow healthy hair, including zinc and iron.

    Soybeans, which contain a polyamine compound called spermidine, may be particularly effective for hair growth. Research on hair follicles has found that spermidine may help to extend the growth phase of the hair cycle.

Habits and Lifestyle Choices

In many ways, the health of your hair is a reflection of your general health. Although maintaining healthy habits won’t block the effects of DHT on your hair, living a balanced lifestyle may have a positive effect on your hair growth as a whole. Try to:

  • Protect your hair from UV radiation. Most people are familiar with the negative effects that excessive sun exposure can have on your skin. Far fewer understand that exposure to UV radiation can also damage your hair.

    Research has found that excessive sun exposure can damage the structure of your hair shaft, causing degradation and loss of important structural proteins that provide hair with its strength and integrity.

    When you’re outside on a sunny day, try to protect your hair by wearing a hat. As well as caring for your hair, it’s important to protect your skin from UV damage by applying broad spectrum, SPF 30+ sunscreen whenever you’re out in the sun.

  • Stop smoking. Although smoking doesn’t appear to be linked to male pattern baldness, research has found that the chemicals in cigarette smoke can cause damage to the DNA of your hair.

    If you smoke, it’s best to quit, not only for your hair but also for your general health. Our guide to quitting smoking lists techniques that you can use to give up smoking, deal with nicotine cravings and keep yourself away from tobacco for good.

  • Limit stress. Stress, anxiety and traumatic experiences can lead to a form of hair loss called telogen effluvium. While this won’t cause permanent hair loss like male pattern baldness, it can cause diffuse thinning that can last for several months at a time.

    If you’re feeling very stressed and notice that your hair is falling out faster than normal, telogen effluvium could be the reason. Our guide to stress-related hair loss talks about this form of hair loss, as well as the steps that you can take to avoid it.

  • Check your medications. Certain medications, such as beta-blockers and others, can trigger telogen effluvium hair loss. Others, such as testosterone, may worsen hair loss from male pattern baldness by increasing DHT levels.

    If you’re beginning to lose your hair, it’s worth checking to see if any of your medications could be responsible. If hair loss is a listed side effect, it’s best to talk to your healthcare provider to learn more about your options. 

In Conclusion

Hair growth is a complex process with lots of different moving parts, from your hormones to your intake of hair-friendly vitamins, minerals and nutrients. 

If you’re losing your hair due to male pattern baldness, your first priority should be stopping any damage caused by DHT. The most effective way to do this is by taking finasteride every day to prevent your body from converting testosterone to DHT.

For general hair health and optimal growth, aim for a combination of healthy foods, hair growth supplements, good habits and topical medications such as minoxidil. Over the long term, these may help to improve your hair’s growth, strength, thickness and overall appearance.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.