Article by Celia Schatzman, Byrdie, May 02, 2022

What’s the only thing that, if you watch it, seems to grow slower than grass? Your hair, of course. When you’re trying to grow out a cut or reach Rapunzel-worthy lengths, it often seems like your hair just isn’t getting any longer.

It might be hard to believe, but for the most part, hair grows at the same speed—no matter how many times you’ve Googled “how much should my hair grow in a month?” We asked board-certified dermatologist Panos Vasiloudes, MD, Ph.D., and trichologist Helen Reavey, to help us answer the question once and for all and to spill the hair lengthening secrets you’ve been wondering about. Keep reading for what they had to say.

How Much Can Hair Grow in a Month?

"The scalp hair grows at about 1/3 to 1/2 inch per month on average, so about four to six inches per year for the hair on your head," says Vasiloudes. Of course, there are a few factors at play that can affect that number. “There are variations depending on, for example, getting the right nutrients or stress in their life,” explains Reavey. “Things like that can slow it down.” 

That’s the deal with hair on your head—keep in mind that hair growth rates vary based on anatomic location. “Some hair follicles are dormant, meaning the hair is not dead but rather ‘asleep’ for a period ranging between two to 12 months. Others are terminal, as in actively growing, and some do not grow at all or only grow after stimulation under various conditions,” says Vasiloudes.

What Are the Factors Behind Hair Growth?

Each person’s hair growth is as complex and individual as they are. “A multitude of factors influence hair growth rate. The primary factors are genetics and hormones,” Vasiloudes says. “In addition, nutrition, environment, and age can also impact hair growth," he notes, along with stress, medications, hormones, diseases, and illness.

What Can Stop Hair Growth?

Your Genes

If your hair isn't growing at the rate you'd like, it might be entirely out of your control. “Primarily the predisposition for hereditary hair loss, which happens from an interaction between genetics and hormones, [stops hair growth],” Vasiloudes says.

Your Health

Vasiloudes notes that "diseases and certain medications can cause the hair to stop growing. Sudden hair loss after major illness and surgeries is called telogen effluvium and is very well described in the medical literature, just like nail changes after such shock to the body.” Additionally, cancer treatment is another common trigger, as the medications can inhibit hair growth to the degree of complete baldness.

Your Lifestyle

While you can’t control your genes, you can control your lifestyle. “When you’re stressed, your minerals go to protect your body and your hair is the last to get anything,” Reavey says. “The nutrients and vitamins go to protect all the other organs and it can stop blood supply from going into the hair, and then that can lead to hair loss. Stress can really cause a lot of hair loss.”

The Environment

The environment also takes a toll on hair growth. “I always say protect your scalp,” Reavey says. That means wearing a hat while outside, since too much fun in the sun can damage strands and dry out the scalp.

Your Water

If your home has water that’s too hard or soft, it’s worth investing in a filter for your shower. Hard water can curb hair growth, since minerals in the water, such as copper, can make hair more brittle and dry, leading to a thirsty scalp.1 “Soft water will make it really difficult to rinse out your product properly and it'll make the hair feel flatter and greasier,” Reavey says. 

Product Buildup

Product buildup can also hinder hair growth. This is especially true of most dry shampoos: “Most have aerosol, alcohol, and talc, which can block the hair follicles,” Reavey says. “Alcohol is drying, and the dry shampoo sits on your scalp." Shampooing regularly is key to a healthy scalp and hair. “If you're going to jump in the shower, don't just wet your hair in there,” she cautions. “When you wet your hair, those minerals are sitting on the hair and then it becomes dry and brittle. You need to shampoo to remove minerals. I don't think people realize how important it is to keep the scalp clean—but not too clean, like using a clarifying shampoo or something stripping.”

A Nutrient Deficiency

If your hair isn’t growing as fast as it used to, it’s a good idea to see a dermatologist or trichologist for bloodwork to see if you’re deficient in a particular nutrient. “When your hair is more brittle than usual or your nails are breaking, that's usually a sign that something's missing, so check with your doctor,” advises Reavey. Eating enough protein is crucial since it’s the building block of hair. And many people are low in iron; in those cases, a simple dietary adjustment can help with hair growth. 

How Can You Encourage Your Hair to Grow Faster?

“A holistic approach to wellness is paramount,” Vasiloudes says. “Good lifestyle choices and high quality, primary, unprocessed organic food can impact hair growth positively, [as can] drinking plenty of good quality spring water from different sources in the world. These are simple ways to provide our body with micronutrients.”

If slow hair growth has become a struggle for you, Vasiloudes recommends seeking out treatment at a Harklinikken clinic. “Lars Skjoth has developed novel and pioneering approaches to deliver plant-based extracts coupled with proprietary natural constituents from cow’s milk, fruits, and roots, that are rich in diverse elements and natural growth factors in a preservative-free fashion, right to the root of the hair follicles. By doing so, Skjoth has delivered pioneering quantifiable results over the past three decades.”

A go-to hair growth helper for Reavey is dermarolling, a microneedling device that can be used at home. “You want to go for the smallest needle size,” she says. “It creates micro fractures in the skin and that makes the stem cells produce more growth hormones. That's why the cell turnover is much faster on the skin, and the same applies to the scalp.” She recommends doing it once a week on a clean scalp. Separate the hair into sections and do small movements up and down the scalp, focusing on areas in the hairline where you’re experiencing hair loss.  

Hair supplements can help, but keep in mind that it takes at least three months to see results. To see if the pills you’re popping are actually making a difference, Reavey suggests monitoring your nails, since it’s much easier to notice when your nails are growing faster than your hair. “Supplements give you a boost and ensure that you are getting the right nutrients,” she says. 

The Final Takeaway

There’s no quick fix to getting your hair to grow faster. “It’s all about that 360-degree holistic approach,” Reavey says. Living a healthy lifestyle by soothing stress and loading your plate with healthy, well-balanced meals will go a long way to helping you get long hair.