40 Bad Haircut Ideas That, For Whatever Reason, Were Actually Tried Out (New Pics)

Of course, the reassuring thing is that hair grows back. However, it often takes longer than we'd like to. Celebrity hairstylist Kristen Shaw said that, "If you've cut your hair to just below your chin, that would take typically 5 or 6 inches to grow past your shoulders, so it will take 10-12 months."

To make matters even worse, this rate is just an average that can be negatively impacted by a number of factors, some of which are not easy fixes. "I find that women's hormones play a large role, and with the rise of things like autoimmune/adrenal burnout for women, these have been a recurring theme with my clients who experience slow growth and/or hair loss," Shaw explained.

Other factors which may inhibit growth, according to NYC-based dermatologist Francesca Fusco, MD, include poor nutrition, yo-yo dieting, and improper or inadequate hair care. "Maintaining good hair health internally as well as externally are important for optimal growth," she said. To this list, Jon Reyman, Founder of Los Angeles-based salon Spoke & Weal, added suboptimal scalp health and some medications as well.

Timing makes a difference in how fast your hair grows, too. "Usually in summer months hair grows a little faster due to circulation," Reyman said, noting that studies by The National Institute of Health show it can grow 10 percent faster in the sunniest season. He gave slightly better odds of recovery than Shaw, too. "If the bob is chin-length, it should take 3-4 months to grow to your shoulders." So perhaps the real number lies somewhere in the middle.

If you want to make your hair grow faster, there are things you can do to help that. First, ensure you're getting proper nutrients from your diet.

"Health starts from within, so lots of fruits and veggies, and organic, pastured meat, along with the right kinds of fats will help your body function to its fullest potential," Shaw said. But other lifestyle factors matter, too.

"Maintain physical and mental wellbeing—stop smoking, get rest, and minimize stress," Reyman added. "An unhealthy person is usually not experiencing higher than average hair or nail growth."

Both Shaw and Dr. Fusco also recommended the supplement Nutrafol ($88), and Shaw likes the Moon Juice SuperHair ($60) as well.

"They're packed with amazing ingredients to boost hair growth and strength," she said. "I've seen them almost double hair growth."

Next, it might be a good idea to schedule regular trims. However, Reyman noted that it's important not to confuse length and density.

"You may need very regular haircuts when your hair is growing to manage density but not length," he said. "If you want to keep your length, find an excellent hairdresser who can manage density well. Removing weight can help hair look great and be more manageable."