When It Comes to Nanoxidil vs. Minoxidil for Hair Growth, Experts Have Strong Opinions

If you're dealing with hair loss, take heart in knowing that you're not alone. There are many different types, but the most common, androgenic alopecia (AKA male or female pattern baldness), is estimated to affect up to 80 million Americans.

And if you're dealing with this extremely common—and potentially extremely upsetting—condition, you're probably already well aware that there are, oh, zillions of products promising longer, thicker, fuller, strands. But there's only one ingredient out there that's FDA-approved to *actually* treat pattern hair loss: topical minoxidil. Minoxidil has been around for decades, but now a new kid on the block, nanoxidil, is making similar claims.

Close-sounding names aside, is it legit? What is the difference between the two, and how should you decide which one to use? Ahead, trichologist Isfahan Chambers-Harris, Ph.D., dermatologist Craig Ziering, DO, and doctor of nursing Jodi LoGerfo, DNP, offer their takes on nanoxidil versus minoxidil.

What Is Minoxidil?

Now a popular treatment for hair loss, minoxidil was initially developed as a drug for hypertension in the 1970s, explains Chambers-Harris. One of its side effects was excessive hair growth on the body, which ultimately led to it being developed as a topical medication used to treat androgenetic alopecia in both males and females, she says. Topical minoxidil is available over the counter and in prescription products, at varying concentrations, and under brand names and generic versions. The most popular? Rogaine.

How It Works

A hair follicle goes through three phases: anagen (growth), catagen (transition), and telogen, the resting and shedding phase, explains Ziering. "Minoxidil shortens the telogen phase, causing the hair to enter the anagen, or growing, stage more quickly," he explains. "Each hair follicle spends less time in a resting state and more time growing from your scalp." On top of that, "minoxidil is a vasodilator, meaning it widens the blood vessels to deliver more oxygen-rich blood to the hair follicles," says LoGerfo. This can also support healthy growth.

What Is Nanoxidil?

It's not just the names that sound the same: The molecular composition of nanoxidil is nearly identical to that of minoxidil. "This is a newer topical hair loss treatment and compound [with] a similar molecular structure to minoxidil," explains Ziering. The only difference? Nanoxidil has one fewer carbon chain, which lowers its molecular weight and theoretically improves its absorption into the scalp. It also bears mentioning that nanoxidil is only being sold by one company, DS Laboratories, formulated in a topical serum at a 5 percent concentration.

How It Works

It's thought that nanoxidil works like minoxidil by increasing blood flow and nutrient delivery to the hair follicle, which may help stimulate growth, says Ziering. The serum in which it's found also contains other ingredients, such as retinol to further boost absorption into the skin and anti-inflammatory copper peptides. The big (BIG) caveat: "There are no clinical trial data or studies published for this treatment," says LoGerfo, who is outspokenly skeptical of the ingredient.

Nanoxidil vs. Minoxidil: Which Is Best For You?

In related news, there are also no head-to-head studies comparing the efficacy of nanoxidil and minoxidil directly, points out Ziering. DS Laboratories claims that nanoxidil has fewer side effects than minoxidil (which can include burning, itching, and irritation at the site of application), but again, that hasn't been independently proven. Theoretically, nanoxidil can treat both the vertex (the crown) and the hairline, whereas minoxidil only treats the vertex, says Chambers-Harris. Still, she, too, notes that there isn't enough data or info on the ingredient or its long-term effects. The manufacturer of nanoxidil also claims that it can work to treat both androgenic alopecia and alopecia areata, another form of hair loss caused by an autoimmune disease.

The Final Takeaway

First and foremost, if you're experiencing hair loss of any kind, it's important to seek professional help. There are many different types of hair loss and reasons for it, so understanding what's causing it is imperative for figuring out the right treatment plan, which often requires taking a multi-prong approach.

All that being said, the experts we spoke with all expressed varying degrees of skepticism toward nanoxidil, given its lack of scientific data and FDA approval—particularly as compared to minoxidil, which has a well-proven track record. Make sure to consult with a derm or trichologist first. But, when in doubt, opting for the tried-and-true option is the safer way to go.