Growing a beard isn’t a particularly tall task.

But even after stopping shaving, you may have doubts as to why your beard doesn’t match the vision you had in your head. Experts say beard growth is largely determined by genetics, though there are some steps you can take to ensure your beard has you looking the way you want it to.

Here’s what you need to know.

How to grow facial hair

The most important factors in beard growth are “genetics, age and androgen sensitivity,” according to Dmitri Wall, a dermatologist and associate professor at University College Dublin. Androgens, a group of hormones including testosterone and dihydrotestosterone (DHT), regulate the development and maintenance of traits typically associated with males, though everyone produces it. Wall said beard follicles are strongly influenced by DHT, which is why beard density often continues to evolve after puberty.

“But there is a limit to what can be modified if someone is not genetically programmed to develop a dense beard,” Wall said.

Some people rely on medications to stimulate beard growth, though they aren’t without side effects.

Topical minoxidil, which Wall said is probably the best-supported drug option for beard enhancement, remains off label, and while evidence suggests it can improve facial hair growth, it can also cause irritation or dryness or unwanted hair growth in distant areas. Another commonly used treatment, Tretinoin can help the body absorb minoxidil, though it can also cause significant irritation.

Beard transplantation is also an option, though Wall said it requires careful assessment by a specialized surgeon beforehand. Transplanted hair, he added, retains many of the characteristics – direction, curl, density – of the donor, and poorly planned transplantation can lead to a visibly incongruent fit.

What is the 90-day beard rule?

A widely accepted guideline for beard growth, the 90-day rule stipulates a person should allow their beard to grow for around three months before deciding whether it is too patchy, or before committing to a final shape. 

Wall said this rule is a “sensible practical concept” rather than a “biological threshold.”

“Beard hairs do not all grow at the same rate, and early trimming can make people judge their beard before it has had a fair chance to show its density,” he said.

Talk with a dermatologist or other licensed medical provider to figure out the best course (coarse?) of treatment for you.