How To Get Longer And Thicker Hair, According To Science

Have you ever watched a rom-com and dreamed of having the leading actress' beautiful long hair? (Reese Witherspoon, we're looking at you). You are not alone. So many women have longed to do that slow-motion movie-style hair toss with long luscious locks, but for many of us, having long thick hair seems like an unattainable goal, and the pandemic didn't help. According to the medical journal Lancet, 22 percent of women in one of their studies reported hair loss was one of the symptoms of COVID-19. Generally, how fast your hair grows depends on factors like age, hair type, genetics, and overall health (per Healthline).

But don't fret just yet; science has come to the rescue. Thanks to research, there are so many ways that you can promote hair growth, and these may include adding more protein to your diet and changing up your hair care routine. Of course, finding the right way to make your hair longer and thicker may take trial and error and a good dose of patience, but once you discover what works for you, you won't regret going on the journey. We've collated some of the best science-based tips to help you have longer, thicker hair faster, so you can be on your way to doing that hair toss you've always dreamed of doing.

While some hairdressers say you should wash your hair daily, others say you should wait as long as you can before washing your hair, so it's hard to know what's right. So what do you do? According to celebrity hair expert and trichologist Guy Parsons, the best way to know how often to wash your hair is by experimenting with a hair wash schedule and observing the results. "You should wash your hair whenever your scalp feels greasy, dirty, or smelly, regardless of your hair type," Parsons told Good to Know.

While women with fine hair will usually wash their hair frequently because of its susceptibility to greasiness, Parson says those with thick hair should also stick to a regular cleansing routine. "I prefer clients to wash thick hair more often as it can contain bacteria, oil from sebaceous glands, dead skin, and it needs to be cleaned more often and thoroughly rinsed to remove all of this," says Parsons.

The bottom line is that if you don't wash your hair frequently enough, it can result in a dry scalp, but over-washing your hair can make it too greasy. That's why experts emphasize the importance of finding the right balance of time between washes, which requires monitoring your hair closely and seeing which time frame gives you the best results.

If you love a good spa treatment, you'll love this scientifically backed hair growth tip. According to Healthline, scalp massages have been linked with hair growth and thickness because they stimulate blood vessels and stretch out the cells around the hair follicles.

Dermatologist and hair specialist Raechele Cochran Gathers, M.D. says, "Beautiful, strong hair depends on good blood circulation, proper nutrition, and a healthy and supple scalp" (via Mind Body Green). An excellent way to care for your scalp is to get a scalp massage, as it promotes blood circulation, which is needed to encourage oxygen and hair-healthy nutrients associated with hair growth.

A 2016 study on a small sample of men found that a regular scalp massage showed promising results after 24 weeks, as researchers observed that the hair thickness of all participants increased significantly. If that's not enough for you to try one, a second scientific trial of female office workers found that a biweekly scalp massage had "positive effects on stress hormone, blood pressure, and heart rate." So the plus side is, if you don't find a scalp massage beneficial to your growth cycle, it will help reduce stress, making it worth a try.

If you are not a fan of using chemicals to grow your hair, you'll be pleased to discover that essential oils have a range of benefits when it comes to making your hair longer, thicker and healthier. Homeopaths have long sung the praises of essential oils because they are not harsh on the body and can give you great results.

Depending on your desired results, different essential oils can help you grow your hair and improve scalp health. But it's important not to apply essential oils directly on your skin as this can cause skin problems. Instead, dilute them in a carrier oil such as olive oil or melted coconut oil, according to Healthline.

Even though it's more commonly known for its calming effects, you can also use Lavender oil to speed up hair growth. One animal study found that Lavender oil improved the hair growth and thickness of mice, with researchers concluding that Lavender oil could be used as "a hair growth-promoting agent" (via Toxicological Research).

Another study published in the National Library of Medicine found that essential oils showed promise in helping promote hair growth. The study included jojoba oil, rosemary oil, tea tree oil, argan oil, chamomile oil, thyme oil, tea tree oil, and rosemary oil. According to Healthline, using essential oils is as simple as adding tea tree, rosemary, or lime oil into your shampoo or diluting it with jojoba oil as part of your hair care routine.

Our diets impact everything from our mood to energy level, and according to WebMD, what you eat could directly affect your hair growth and thickness. So if you lack specific nutrients, you may need to switch up your diet, which can affect your hair growth cycle.

Omega 3 nutrients are essential for healthy, shiny hair. According to the National Library of Medicine, one study found that Omega-3s fish oils helped promote the hair growth of rodents. Another study published in Wiley Online Library observed that women taking omega-3 and omega-6 supplements for six months had thicker hair. Besides taking supplements, you can get a good dose of omega-3 by adding the right food to your diet. For example, eating more fish like salmon, mackerel, and tuna is an excellent source of Omega 3. You could also sprinkle your choice of flaxseeds, chia seeds, or walnuts into your daily salad. Also, your mom was right; eating your vegetables benefits everything, especially broccoli, cauliflower, and Brussels sprouts, a rich source of Omega 3 that will help promote hair growth (per WebMD).

Since our hair is made out of protein, including enough proteins in your diet is essential for healthy hair, and a protein deficiency can be attributed to hair loss. According to Healthline, a great way to get enough protein is to eat eggs, considered a superfood for obtaining the proper healthy-hair nutrients.

When growing your hair, the last thing you want to do is go to the hairdresser and have it cut; ironically, trimming your hair more every six to eight weeks will help it grow faster. If you want your hair to be long, thick, and strong, you should consult your hairdresser about creating a regular trimming schedule based on your hair type, per Good Housekeeping.

The main problem with not getting your hair cut regularly is split ends. Meri Kate O'Connor, a senior colorist and educator at Eva Scrivo Salon in New York City, says, "When the split goes up the hair shaft, it becomes so thin that it breaks." In addition, the longer you wait between cuts, the more your hair is susceptible to breakage, which is detrimental to hair growth because "once you split your hair, there's no way to repair it," O'Connor told Good Housekeeping.

Unmanageable hair and split or sticky ends are signs that your hair needs a trim, but it's best not to wait for these. "Truthfully, it is best to give your hair a trim before these signs because once you see them, there is already damage done," Philip B, a celebrity hair treatment expert, told Good House Keeping. 

Heating tools like hair straighteners and curling wands are well-loved for their practicality and are the best and most cost-effective way to get that salon look at home. But if you intend to have long, thick healthy hair, think twice before using heat styling tools, as these can hinder hair growth because they dry out your hair and can even cause permanent damage, per Vegamour. Ona Diaz-Santi, a celebrity hairstylist and curl expert, warns that you should avoid heat tools if you want to grow your hair. "Excessive heat styling will dry out the natural luster in the hair and make it brittle," Diaz-Santi told Vegamour.

If you want your hair to feel renewed and healthy, consider breaking up with hair tools, at least for a short time. According to Garnier celebrity hairstylist Millie Morales, even a month without heat styling can help your hair become healthier. "After a month, you will notice an incredible, stronger change in your hair," Morales (via Well and Good). "You would have recovered the hydration, the natural oils of your hair, and would have strengthened the protective layer of the hair," she adds.

Using the right conditioner is one of the best ways to keep your hair hydrated and promote growth. In addition, conditioning your hair after shampooing can improve its texture and make hair easier to manage (per Healthline). According to a report from Johns Hopkins Medicine, using conditioner is one of the most critical steps for a healthy hair regimen.

Hair naturally produces sebum, which acts as a conditioning agent. Unfortunately, shampoo removes sebum, which is why conditioner is seen as the superhero to the rescue. But finding the right conditioner for your hair can be difficult. The first step is to identify your hair type. According to WebMD, there are three general categories: dry, neutral, or oily. Once you know your hair type, choose a conditioner to help balance it and consider how often to use it. For example, if you have dry hair, your hair is more susceptible to breakage and requires a thicker conditioner, and if your scalp is oily, you should use less conditioner and focus on the ends. Those with more neutral hair can opt for a standard conditioner.

Once you've tried a balanced diet and the proper hair care strategies to grow thick long hair, you might feel like you want to give your hair another push in the right direction. Various vitamins and supplements can help your hair look smoother and grow faster. "When seeking out a hair growth supplement, you want to consider clinically effective, medical-grade ingredients," advises Dr. Kim Nichols, a board-certified dermatologist, told Marie Claire. "The best ingredients for hair growth include B vitamins, vitamin D, vitamin E, vitamin C, zinc, and iron," adds Nichols.

A 2010 study found that after taking vitamin E supplements for eight months, 34 percent of participants increased an increase in hair growth. Vitamin C is also great for hair growth. "Vitamin C increases the absorption of iron, which is one of the most critical nutrients for your hair," says William Gaunitz, a certified trichologist (via Mind Body Green).

The supplement industry is not regulated by the Food and Drug Administration (FDA) in the same way as "conventional" drugs. For this reason, consult a medical professional before taking supplements, as some may interfere with other medications and may not suit your health needs.

According to a 2017 study, protein deficiency has been attributed to reduced hair growth. The best way to increase protein intake is by eating foods like certain vegetables, nuts, yogurt, and fish (via Healthline). "Your daily protein intake should be 30% of your total calorie count. A diet rich in protein is crucial for healthy hair growth," explains Dr. Zeel Gandhi, per Skinkraft. Although some women prefer protein supplements for hair growth, using topical protein treatments is another method that works as it nourishes hair, protects it from damage, and reduces breakage, per Skinkraft.

You could opt for store-bought shampoos and masks if you want to incorporate topical protein treatments into your hair routine. If you'd like a salon-based treatment, ask your hairdresser about keratin treatment, a protein usually used at salons because it is chemical based. For those, who prefer a more natural solution, you could make a homemade topical protein treatment using eggs and yogurt. "Beat the egg and yogurt in a bowl to form a smooth paste. Apply this to your scalp and hair. Wash with a mild shampoo after 30 minutes to get smooth and shiny hair," advises SkinKraft. At-home protein treatment can be used on a regular basis, weekly or monthly, depending on the condition of your hair and scalp, according to Byrdie.

If you love caffeine, you'll be happy to know that your hair does too. A 2020 study found caffeine to promote hair growth, suggesting that it could be a great alternative to drug-based approaches. Caffeine is a stimulant that increases blood circulation to hair follicles, helping them grow faster and thicker (via Healthline).

So, how do you get caffeine into your hair? Unfortunately, the answer is not to consume more coffee but to use external caffeine treatments like caffeine-infused shampoo. Lisa Caddy, a trichologist, told Stylist that she recommends being patient when judging the results of caffeine hair treatments like shampoos. "It's important that you give it a few months to work, though, as it can take a while to notice the difference. That way, you can judge results for yourself," advised Caddy.

A highly rated over-the-counter caffeine shampoo is the German-made Alpecin shampoo. For under $15, it combines caffeine with niacin and zinc to help promote hair growth and thickness.

One of the easiest and most accessible ways to improve your hair's overall health is to use hair serums as part of your beauty regime. Although serums are not a miracle treatment, they can help your scalp and encourage hair growth, per Cosmpolitan. According to Health, they work by "activating blood vessels to carry oxygen to the follicle's root and accelerating hair growth."

Hairstylist Anthony Dickey told Mind Body Green, "if you are trying to grow it longer, you need to keep it moisturized," and serums do just that. Most serums include fatty-acid-rich oils that benefit the hair by providing strands with hydration, and Dickey says this is especially beneficial for those with dry or brittle hair. For best results, trichologist Tiffany Young recommends looking for serums with natural ingredients like castor, rosemary, pumpkin seed oil, or menthol, as these as these assist in treating dandruff, fungal infections, dryness, and some forms of alopecia, per Health.

Like with all topical hair treatments, it's important to remember that hair serums don't work overnight and that it may take time to see visible results. Speak to a hair expert about finding the right hair serum for your scalp and hair type. If, at first, you don't succeed, don't give up on finding the best product for you, as this can take patience and a willingness to experiment with a variety of products.