Most techniques to “thicken” the eyebrow hair are actually meant to give the appearance of thicker eyebrows, without really affecting the eyebrow hair growth itself. Finally, this suits your purpose of course, but it is a fact that you should keep in mind. The growth of eyebrow hair, just like any other hair on your body, is determined by your genes, and cannot simply be increased at will. Some people naturally have fine, light eyebrows. If you are one of those people, you will simply have to accept it and work with your eyebrows to the extent possible. You can however ensure that your diet and lifestyle are not somehow causing your eyebrows to be thinner than they naturally are.
First of all, ensure that your diet is healthy and balanced, so that you get all the possible nutrients you may need. Nutritional deficiencies tend to affect the hair first, because the body uses scarce resources for more important organs and functions first. If you are not getting enough of a particular nutrient, your hair will usually be the first to suffer. Second, avoid subjecting your eyebrows to any cosmetic treatments and procedures for at least a couple of weeks. Avoid plucking, threading, or waxing your eyebrows, so that they can grow back fully. Also avoid using make up, as it can sometimes irritate sensitive skin or cause hair to weaken. Stopping shaping your eyebrows will mainly result in them growing bigger and less clearly defined – once this happens, you can start shaping them again, ensuring this time that they are not too thin. If the growth of the eyebrows also gets thicker, then you can probably safely assume that the make up you were using was part of the problem. Switch to a different brand, and ensure that you never use cheap or expired products on your face.
Finally, you need to use the right make up on your eyebrows so that they look thicker without looking fake. Drawing on your eyebrows with a pencil usually gives a fake, obviously drawn on look. Instead, brush on a little eyebrow powder – this will not create such a dark line as an eyebrow pencil, and looks more natural for precisely that reason. Powder will not create a fake line, but will accentuate and darken your actual eyebrow hairs. You can also try using an eyebrow waxing or gel, but this is more difficult to use, and may not be suitable for a thin growth.