Conditioner, balm, butter, cream—no matter what you call it ... and to even promote beard growth and shine. You might find this more commonly in balms and heavy-set styling products.
However, the study did not investigate beard growth specifically, and there was no evidence that the topical cream would work on people without the genetic condition or without a vitamin D deficiency.
I’ve never really had a problem growing a full beard as much as maintaining it without the itchiness or irritation. My facial hair is rather coarse and, at a certain length, has a slight curl to it.