Beard growth supplements, is it helpful? Any side effect?

Facial hair is a genetic trait that you inherited from yourFUE mother or father. It is not generally related to hormones or a disease process. Some may try to use Rogaine but without great success. You may want to consult with a doctor for possible surgical options.

Beard growth is genetically determined, and there is currently no supplement that can help you grow one.You can try topical minoxidil as a start.The only permanent solution is getting a beard transplant from an experienced hair restoration physician.

Not having a full beard may be a downer for quite a few patients, therefore, at times this leads them to find unproven alternatives lurking around the web. It is quite obvious that 'treatments' and 'supplements' promoted by many 'influencers' may not have good effects, but in return they may cause harm.
So do supplements really work?
This completely relies on the supplement in question. If they are supplements offered by physicians with a scientific backing that they work, then, they most definitely do their job. However, supplements can only help boost hair when there is hair fall due to lack or imbalance of nutrients in the body and they cannot miraculously help resolve hair redundancy of every kind.
Will supplements work for the beard?
In most cases, if the patient is young it is prescribed once hormonal imbalance and other co-morbidities have been rules out. Nevertheless, it may not work for everyone or patients in the older age spectrum.
What are the other options?
The safest option to get the results one desires is via a beard transplant. A beard transplant will ensure that the grafts are brought to the beard region where there is thinning and result in a fuller beard.

There is nothing that you can apply that will produce a good beard. Beard transplants can, however, produce a good beard

Supplements are usually not very effective, however I have found that clients who use rogaine for hair growth sometimes grow facial hair. So you may try rogaine and see if you grow some facial hair.

Hair transplants from the scalp to the face often can work to make a fuller looking beard. Unless you have testosterone deficiency, there is no known supplement treatmen, in my opinion,  that will increase beard growth.