The Pro's Guide to Growing Out an Undercut

While the popular undercut hairstyle can be polarizing, no one can deny its versatility. The look, wherein the under portion of the hair is cut super short or shaved, flutters in and out of trend due to its edgy-meets-sophisticated style. Wear the hair down, and it looks like a classic pixie, lob, or bob, but pulling the hair up or back reveals a fun little secret of shorter hair, sometimes adorned with multi-dimensional shaved layers, rainbow-colored hues, and even stenciled-in designs.

Whether the upkeep of routine haircuts becomes too high maintenance or you want longer hair and a different style, growing out an undercut can be done without an awkward stage with the right trips and tricks—and plenty of patience.

Ahead, we're sharing everything you'll want to know about growing out an undercut the right way—trust us, it makes all the difference.

How to Grow Out an Undercut

Labrecque explains that a traditional undercut is a unique hairstyle where the hair hits from the parietal bone to the occipital bone, and the hair beneath that stretch is cut very short. "The undercut is stylish and current again, and it's also a good way to take away excessive bulk, especially on those with coarser hair, so that the hair assumes a less wide appearance," Labrecque says. "It is also a style you can hide when you want to be conservative or exaggerate when your look warrants trendiness or edge." But if you're tired of an undercut and want to grow it out, you'll need to be patient and give your hair plenty of time and TLC.

The goal in growing out an undercut is to get the hair to be the same length throughout. Since the layers of hair closest to the nape of the neck are cut shorter than the rest, it can take a few months to up to one year for the cut to fully grow out, depending on the hair's natural hair growth cycle and texture. But another issue with growing out an undercut is that the hair can start to take on a reverse mushroom effect as the hair grows, often refusing to lay down flat. At the same time, the upper lengths stay detached and long.

How long it takes the hair to grow back in also depends on how short it was cut. Cosmillo says that it takes approximately eight weeks for most people to see about one inch of regrowth, "so it will take about four to six months to get the hair to shoulder length." Naturally, the longer you want your hair to grow, the longer it will take to grow out an undercut.

While you might think that growing out an undercut will leave the hair looking weird, Labrecque says the overall style should fare just fine. "What's growing out is pretty much hidden, but it can result in some widening of the hair for those with coarse strands," he shares. Cosmillo adds that the first few inches of hair can also stick out or fluff up, so it's important to consider the right way to style your hair during the grow-out process.

The Best Products for Growing Out an Undercut

For hair in transition after an undercut, there are plenty of styling products to keep on hand to help make the transition to your next style a little more manageable. Labrecque says a good hair gel is super helpful. "It keeps the shorter hairs and those that stick up in place while the hair grows in so that everything remains tight." He also adds that pomades are ideal for controlling the hair. "There's little drying with them unless you have very curly hair." Mousse and a medium-to-strong hold hairspray, like Paul Labrecque Daily Finish ($28), are essential styling products for an undercut as it grows out, especially when wearing the hair back and holding it exactly where you want it. 

Barrettes and mini hair clips are also easy, fun ways to pull back pieces of hair that are growing out and keep them out of the way. So are bobby pins, like the ones from Hair Edit, which Cosmillo says can keep the regrowth in place for a more sleek look. Headbands and headscarves can help keep the hair looking clean and neat as it grows out by camouflaging the shorter hair.

Although heat can do a number on the hair, Cosmillo says blow-drying hair growing out can help it. "You'll want to use a product with control, like hOURS Full-Time Plumping Mousse ($27) on wet hair, and blow dry it with a paddle boar brush in a downward direction. This will help smooth and keep it in place as best as possible." Then, once there are a few inches of regrowth, start incorporating it into a low ponytail, bun, or braid. "To capture the shorter strands, do a double-pony method," she advises. "Section off the back half of the hair taut with a boar bristle brush, then secure it with an elastic. This will keep the small hairs from buckling and popping out of the ponytail. Then, pull back the front sections of your hair, securing them to the pony with a second elastic. Finish hairspray at the nape to keep everything in place."

To help reinforce the hair and scalp so they are at their healthiest, add a hair supplement or vitamin, such as Nutrafol ($88) and Joyce Giraud Ultimate Hair Strength Pro Supplement ($50), to your daily haircare routine. While each supplement contains a unique blend of ingredients, most feature hair-friendly vitamins, biotin, collagen, and omegas that help the hair become stronger, shinier, and longer after consistent use for at least a few months.

Styling Tips While Growing Out Hair

An arsenal of good hair products can help hide hair in the growing-out phases of an undercut but don't discount the power of switching up how you wear your hair. Try changing up the part to reveal less of the undercut. Labrecque says the closer the hair part is to the undercut, the more it will be revealed. The further away you place the part from the undercut, the more you hide it." Cosmillo agrees and says that the simple act of switching up the part, which works equally as well for straight and curly undercuts in the growing-out phase, adds more hair above the section you're growing out to hide hairs that might poke through a thinner layer of hair.

Even if you are in the process of growing out an undercut, it's still super important to get routine trims. While regular trims and cuts won't make the hair grow any faster, they will help keep it even and healthy and eliminate dry, damaged, brittle, and split ends. So, rather than waiting for the undercut to be completely grown out, frequent trims every eight weeks will help keep the hair looking fresh and tidy.