The 5 Best Hair Growth Serums

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Regardless of your age, hair loss or thinning is something that can happen to anyone. "It can be caused by an underlying thyroid disease, anemia, vitamin deficiencies, or autoimmune conditions," explains Dr. Joshua Zeichner, MD, a New York City-based dermatologist. "Significant physical or emotional stress may also lead to a form of hair thinning known as telogen effluvium," while scalp infections can also be a contributing factor. And though there are many different types of treatments, trying out one of the best hair growth serums is a good place to start.

Serums in the form of oils and foams tend to have the highest concentration of medicine that can combat hair loss and thinning. One of the most common ingredients to look for is called minoxidil, which has been clinically shown to improve thinning hair. You can find this ingredient in products like Rogaine, and it's among the most effective as far as over-the-counter treatments go. But minoxidil isn't the only ingredient that can help reverse hair loss. Biotin, for example, is often used to help strengthen brittle hair and nails; and while there is some evidence that biotin can be used to help treat hair loss, researchers admit there's a lack of sufficient proof. Applying caffeine topically has been proven to help treat hair loss, also, so it is another ingredient you can find in over-the-counter hair growth products.

Scroll on to discover five of the best hair serums to help treat hair loss.

1. Best Hair Regrowth Serum For Women

There's a reason why Rogaine is such a go-to for treating hair loss — it actually works. Case in point? The brand's 5% Minoxidil Topical Aerosol Hair Regrowth Treatment. It contains minoxidil to help stimulate hair growth and thickness, but it also works magic on your scalp: A healthy scalp is the key to healthy hair, you see, and the blend of alpha hydroxy acids in Rogaine's formula gently exfoliate, creating the optimal environment for hair to grow. After the AHAs work their deep-cleaning magic, a blend of botanical extracts and emollients condition and moisturize your scalp.

It comes in easy-to-use spray form and only requires the application of half a capful a day. Though the results won't be immediate, they'll probably be the most effective you can get from an over-the-counter treatment. Expect to see noticeably thicker hair and fewer sparse patches within three to six months.

"Works beautifully!" one reviewer raves. "I gained twice as much hair ... more than I expected! It does not irritate my scalp and it's not greasy. Easy to use and only need once a day ... Also, I saw new growth within 2 months."

2. Best Hair Regrowth Serum For Men

Compare Basic Care's Minoxidil Topical Solution USP, 5% Hair Regrowth to Men's Rogaine — it's basically the generic form of the product. At a cheaper price point, you get six months worth of the same 5% minoxidil formula that helps stimulate new hair growth. It has more of a traditional serum consistency, being a liquid, and it comes with a convenient dropper for targeted application (though you can get it in foam form, too, if that's your preference). Expect results anywhere between two and six months.

Basic Care also makes two formulas for women: one with a 2% concentration of minoxidil and one with 5%.

"I had a slight bald spot on crown, receding hairline in front, as well as thinning hair on top in general. These generic topical Minoxidil products have given me back the thick head of hair I had in my twenties," reports one happy customer.

3. Best Hair Serum For A Healthy Scalp

In Pura D'Or's Hair Thinning Therapy Energizing Scalp Serum, biotin, apple stem cells, and caffeine work together work to stimulate hair follicles, leading to increased thickness and possibly even regrowth. The serum also contains DHT blockers — DHT is a hormone that can trigger hair loss if there's an increased amount in your body, so a DHT blocker can actually help prevent hormonal hair loss. Argan oil, tea tree, and other antioxidants are also included in the formula to help nourish and exfoliate your scalp, creating a healthy environment for hair to thrive.

"I’ve been using Pura [D'or] scalp serum for a few years now and I don’t know what I’d do without it! My hair was falling out because of medicine I had to take and using the scalp serum slowed down the hair loss and helped my hair grow," writes one reviewer.

4. Best Biotin Serum For Stronger Hair

The Pureauty Naturals Biotin Hair Growth Serum uses a blend of biotin and pro-vitamin B5 to strengthen hair. Since it doesn't contain any type of medicated ingredient, you shouldn't expect hair regrowth, per se; however, if your primary concern is hair that's weak or thinning — which is perhaps contributing to the appearance of sparse hair — this will help nourish it back to life.

One reviewer says, "I have thin blonde hair and have tried finding a product that will help my hair be less brittle after styling daily. After using this for a few weeks I have noticed how soft and stronger my hair is at the ends... An extra bonus is the minty smell. It makes you feel very refreshed."

5. A Serum That Uses Pea Sprout Extract To Promote Hair Regrowth

Some hair loss is localized to one part of your scalp so it doesn't require a ton of product to treat. If that's the case with you, consider reaching for this HairGenics Pronexa serum. It comes in a little bottle with a convenient dropper, so it's easy to apply the serum in smaller, more concentrated areas. The star ingredient here is a patented form of pea sprout extract, which the brand says is effective at treating hair loss. Full disclosure: Though this serum has rave reviews from customers — it boasts a 4.5-star rating on Amazon, too — the brand doesn't offer any proof of the clinical studies they claim to have conducted, in which the effectiveness if their formula was found. Basically, you're buying this stuff on the word of your fellow shoppers.

"This product is great and I am already feeling my hair be thicker and stronger! Also, doesn't leave dry hair feeling greasy or oil-y. The substance is a dry feeling liquid that doesn't alter the look or feel of your dry hair," reports one reviewer.

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