There is no definitive answer to this question as each individual’s facial hair grows differently and responds to different treatments differently. Some possible methods that may help improve the appearance of a patchy beard include:
-Using an electric trimmer or shaving razor to evenly trim the hair on your face down to a uniform length. This will make any patches appear less noticeable.
-Taking supplements such as biotin, which are known to promote healthy hair growth.
-Applying topical oils or balms specifically designed for beard care, which can help hydrate and nourish the hair follicles and skin underneath the beard.
Genetics, age, and hormones are the most common causes of patchy beards. A heavy beard wash and conditioner can help your beard grow faster.
How Can I Regrow My Patchy Beard?
A meal plan with lots of vitamins can help to promote facial hair growth if you have an unbalanced diet. A heavy beard wash and conditioner can help your beard grow faster. 
What Causes Beards To Be Patchy?
Genetics, age, and hormones are the most common causes of patchy beards. Most people have little control over age and genetics, however there are ways to promote patchy beard growth and grow a full beard. 
Does Shaving Get Rid Of Patchy Beard?
Give your beard time to grow so that it is the best it can be. If you have a patchy beard, shaving or getting rid of your beard frequently won’t work. Wait until your beard grows to its full potential. 
Is It Possible To Fill In A Patchy Beard?
If you just let the hairs grow longer, a patchy beard can be filled in. This might mean growing a disproportionate beard in some spots, as you maintain the length of your mustache but let the cheeks grow in more. 
Frank Harmenstein is the lead editor of the grooming website Cut Throat Straight Razor, and has over 15 years of experience in the industry. He’s personally tested and reviewed over 200 different straight razors, and has written countless articles on the subject.