Hair-thickening products coat the hair shaft, making the hair appear thicker. The only real difference between adult hair-thickening products and hair-thickening products for children pertains to marketing. Children's products are packaged in eye-catching, child-pleasing containers, and they are scented with child-friendly scents such as bubble gum, blueberry and light floral. In light of the few thickening products that are actually marketed toward children, it is often easier to find adult products. Fortunately, adult products can be used on children safely and effectively.

Purchase thickening shampoos in any department store or salon. Salon brands such as Nexxus, Joico, Paul Mitchell, Fat Hair and others offer thickening shampoos that can be used on children. Pantene offers a department-store version that rated best overall hair-thickening shampoo in a recent lab study conducted by the Good Housekeeping Research Institute. Salon products cost more than department store products, but it is easier to find a shampoo specifically marketed for children in a salon. Shampoos thicken hair by plumping up the diameter of the hair shaft and removing heavy oils that separate and weigh down individual strands.

Thickening conditioners take the plumping process one step further by coating each hair shaft, making it appear thicker and more substantial. The result is thicker, heavier hair. All of the brands mentioned earlier offer thickening shampoos to compliment their shampoos. Thickening conditioners can be a concern for children, especially if their hair is overly fine. Heavy conditioners may build up on the hair, breaking the hair once the buildup becomes too heavy. Avoid thick conditioners or conditioners that build up on the hair. Instead, choose a thickening spray-on conditioner or light conditioning hair rinse for children.

Common, everyday styling products such as spray gels, mousses and glazes can help children's hair appear thicker and are safe to use everyday or after each shampoo. Thickening styling products exist as well. Thickening sprays and creams, applied to damp hair, cause the hair to appear thicker temporarily, or until the next shampoo. Waxes, pastes and pomades applied to dry hair add texture, depth, thickness and volume. Root booster products add volume to thin hair and are safe for children as well.