So my nails are fragile and brittle and I went online to see what I can do about them. I came across a website that encourages silica to those with brittle nails. Little did I know it helps with hair too. It's like biotin. I know biotin has a history of worsening acne-prone skin and that is not something I'm willing to risk. Silica can also be known as equisetum, or horsetail. It sounds gross but if you look it up it is natural.
Check out the reviews people have given it on amazon:
Amazon.com: Horsetail (Natural Silica) 500 Mg 90 Caps: Health & Personal Care

If anyone has tried it please let me know your experience with it. Also make sure you get the equisetum arvense kind which does not contain toxins.