Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 4/27/2021
Noticed your hair looking a little thinner than usual? You’re not alone. Hair loss is a common issue for men, with research published in the journal Dermatologic Surgery stating that more than half of all men develop moderate to extensive hair loss before the age of 50.
Most hair loss in men is due to male pattern baldness — a form of hair loss that develops as a result of your genetics and the effects of the hormone dihydrotestosterone, or DHT.
While the most effective way to block DHT and prevent hair loss is by using medication, taking care of your hair with a shampoo that’s designed to prevent hair loss may help to prevent DHT buildup and stimulate hair growth.
Unfortunately, not all shampoos for treating thinning hair are equally effective. While some use proven, science-based ingredients, others rely more on ingredients that sound good instead of ingredients that actually work.
Below, we’ve explained what you should look for in a shampoo for thinning hair, as well as the most important ingredients to avoid.
We’ve also shared other science-based techniques that you can use to stop hair loss, maintain your existing hair and even stimulate regrowth in areas of your scalp with obvious thinning.
Most hair loss in men is the result of male pattern baldness — a type of hair loss that’s linked to the effects of the hormone dihydrotestosterone, or DHT.
If you’re losing your hair, washing your hair with a shampoo that reduces DHT buildup and protects your follicles can provide an extra level of protection against male pattern baldness.
When it comes to hair loss shampoos, active ingredients matter much more than brand names. Look for science-based ingredients such as saw palmetto and/or ketoconazole, which are linked to reduced DHT levels in studies.
It’s also important to avoid ingredients that can strip away natural oils and damage your hair, such as sodium lauryl sulfate.
As well as using the right shampoo, you’ll get the best results by using proven hair loss medications such as finasteride and minoxidil.
Just like other hair growth products, shampoos designed to prevent hair loss and stimulate hair growth are all about active ingredients.
In fact, the active ingredients used in a hair growth shampoo are far more important than things like the brand name or how much it costs.
When you’re comparing shampoos, it’s important to look for ingredients that are proven to stop hair loss, stimulate hair growth or do both of these things at once.
We’ve listed several science-based ingredients below, along with the current scientific research behind each one. While there’s no need to look for all of these in a shampoo, it’s best to stick to shampoos that contain at least one of the active ingredients listed below.
Ketoconazole is an antifungal medication. It’s available in several different forms, including as a topical treatment for fungal skin and nail infections. You can find ketoconazole in many hair loss shampoos, particularly shampoos designed to control and prevent dandruff.
As a shampoo ingredient, ketoconazole has been linked to hair growth and increases in anagen (growth phase) hair follicles in some studies.
For example, one study published in the journal Dermatology in the late 1990s found that a 2% ketoconazole shampoo improved hair density and the proportion of hair follicles that were in the anagen, or growth, phase of the hair growth cycle.
Interestingly, this study found that ketoconazole shampoo produced similar results to minoxidil, a popular medication for treating hair loss.
A more recent article published in 2004 theorized that ketoconazole (in conjunction with finasteride, another popular and FDA-approved hair loss treatment) could disrupt the pathway for DHT, the hormone that causes male pattern baldness, in the scalp.
Finally, a systematic review published in the journal Dermatologic Therapy analyzed data from seven different studies and concluded that ketoconazole is a promising alternative therapy for treating male pattern baldness.
However, it’s worth noting that of the seven studies analyzed, two of them were animal studies. Additional, higher quality studies are definitely needed to further assess the potential benefits of ketoconazole.
Put simply, although ketoconazole isn’t quite as well studied as hair loss medications, there’s a fair amount of research showing that it’s effective at treating thinning hair.
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Saw palmetto is a supplement that’s made from the fruit of the Serenoa repens plant, a type of palm that grows throughout the southeastern United States. It’s a popular ingredient in hair loss prevention shampoos, including our Thickening Shampoo.
Like with ketoconazole, several studies have found that saw palmetto may help to prevent hair loss and stimulate hair growth in men.
For example, a small study published in the Australasian Journal of Dermatology looked at the effects of topical saw palmetto products on hair growth in men with male pattern baldness.
Over the course of 24 weeks, the men who applied the saw palmetto products saw an increase in hair count, all with limited side effects. However, it’s worth noting that this study didn’t feature a placebo control group.
Another study involving 100 men with mild to moderate male pattern baldness found that a saw palmetto supplement improved hair growth in 38 percent of the men.
Experts believe that saw palmetto may work by inhibiting the enzyme 5-alpha reductase, which is responsible for converting testosterone to DHT.
We’ve talked more about the scientific evidence behind saw palmetto in our guide to using saw palmetto for hair loss.
In addition to ketoconazole and saw palmetto, several other common ingredients in hair growth shampoos may help to promote thickness, prevent hair loss and keep your scalp healthy:
Pyrithione zinc. Pyrithione zinc is widely used as a treatment for issues like dandruff and seborrhoeic dermatitis. However, some research shows that it may also offer hair growth benefits.
In one study, men with mild to moderate hair loss showed a modest improvement in hair count after using a 1% pyrithione zinc shampoo for 26 weeks.
Pumpkin seed oil. Several studies of pumpkin seed oil, a popular natural oil that’s cold pressed from pumpkin seeds, have found that it may help to promote hair growth in men prone to male pattern baldness.
In a study published in 2014, researchers found that men with hair loss who used an oral pumpkin seed oil supplement grew back hair over 24 weeks of treatment, achieving a 40 percent increase in mean hair count.
Researchers believe that pumpkin seed oil’s effects on hair growth may be related to its ability to inhibit the actions of 5-alpha reductase, the enzyme that converts testosterone into DHT.
Rosemary oil. Like pumpkin seed oil, rosemary oil is a popular natural ingredient in hair loss prevention shampoos that’s backed up by a fair amount of research.
In a study published in the journal SKINmed, researchers compared topical rosemary oil and the medication minoxidil as treatments for male pattern baldness.
They found that rosemary oil was just as effective as minoxidil at promoting hair growth over a period of six months, all with a reduced risk of causing side effects such as scalp itching.
Salicylic acid. Although it’s best known as a treatment for acne, salicylic acid may also have benefits for your hair through its ability to wash away sebum that builds up on your scalp over time.
In one study, researchers found that a shampoo containing a combination of ciclopirox olamine and salicylic acid helped to reduce dandruff and seborrhoeic dermatitis, a type of skin irritation that’s associated with itching and potential hair damage.
However, there’s currently no evidence that salicylic acid blocks the effects of DHT or stimulates hair growth.
While the right ingredients can prevent hair loss, stimulate hair growth and promote thicker and healthier hair, the wrong ingredients can have a serious negative impact on how your hair looks and feels.
If you have sensitive skin, it’s important to be aware of sulfates that are used in many common shampoos, including some shampoos designed to stimulate hair growth.
Sulfates are used to help shampoo lather when it’s mixed with water. Although they’re effective at removing dirt and sebum from hair, sulfates often increase frizz and friction. They may also cause irritation in people with sensitive skin or conditions like rosacea.
Common sulfates that are used in shampoos include sodium lauryl sulfate and sodium laureth sulfate.
While it’s not essential to avoid all sulfates, you might want to look for sulfate-free shampoos if you have hair or skin that’s easily irritated.
A good quality shampoo can help to keep your hair moisturized, smooth, strong and healthy, all while helping to reduce hair loss and stimulate hair growth.
However, using the right shampoo is only one step towards preventing thinning and maintaining your hair.
To get the best possible results, it’s important to combine shampoo with science-based hair loss treatments such as minoxidil and finasteride, as well as hair-friendly habits that promote growth and minimize shedding. We’ve discussed these options more below.
Although shampoo can help to keep your hair healthy and prevent thinning, the most effective way to prevent hair loss is by using FDA-approved medication.
Currently, the two most effective medications for treating and preventing hair loss are minoxidil and finasteride.
Minoxidil is a topical medication that comes as a liquid solution or foam. It works by increasing blood flow to your scalp and moving hairs into the anagen, or growth, phase of the hair growth cycle.
We offer minoxidil online. You can learn more about how to use it to treat hair loss in our guide to applying minoxidil for hair growth.
Finasteride is an oral medication for treating hair loss. It works by preventing testosterone from being converted into DHT by the 5-alpha reductase enzyme.
By blocking DHT from being created, finasteride shields your hair follicles from the DHT-related damage that leads to male pattern baldness. It’s highly effective — in one study, men who used finasteride grew almost 30 percent more hair than men who used a placebo.
We offer finasteride online, following a consultation with a licensed healthcare provider who will determine if a prescription is appropriate. You can learn more about what to expect after starting finasteride in our finasteride results timeline guide.
If you’d like to use minoxidil and finasteride together (a combo that’s more effective than either medication on its own), you can access both medications with our Hair Power Pack.
Small, simple changes to your habits and lifestyle can have a big impact on your hair’s growth and thickness. Try to:
Get enough zinc and iron. These minerals play a major role in promoting healthy hair growth.
Use hair growth vitamins. From vitamin A to vitamin E, your body depends on several vitamins to grow healthy hair. We’ve covered which vitamins to focus on in our guide to essential vitamins for optimal hair growth.
If you smoke, make an effort to quit. Research suggests that there’s a link between smoking and hair loss.
Try to minimize stress. Stress can cause a type of hair shedding known as telogen effluvium. Although this form of hair loss isn’t permanent, it can take a major toll on your hair’s appearance in the short term.
Our guide to lifestyle changes for better hair growth goes into more detail about habits to focus on for a healthier head of hair.
When it comes to hair loss shampoos, it’s better to look for active ingredients like saw palmetto and ketoconazole than particular brand names.
Combined with medications like minoxidil and finasteride, these ingredients can slow down the effects of male pattern baldness. In some cases, you may even notice new hairs growing back in areas of your scalp with noticeable thinning.
You can find more information about the most common causes of hair loss and best treatment options for protecting your hair in our full guide to male pattern baldness.