There is no clear evidence of dangerous side effects from using Grecian Formula or other progressive hair dyes when used as directed, according to the U.S. Food and Drug Administration. It has FDA approval solely for external use on the head.
The active ingredient in progressive hair dyes is lead acetate, which is considered safe to use in hair dyes, according to the FDA. However, the FDA does require this product to carry warnings regarding its use. Following the directions carefully ensures that the product does not cause any adverse side effects. Like other cosmetic products, a user should avoid getting this type of hair dye in the eyes, mouth or on broken skin. Skin does not absorb the lead acetate in this product, so contact with unbroken skin is safe, according to the FDA. Additionally, studies show that users experience no increase in lead levels of their blood.
However, some critics are concerned about FDA standards being too lax, says Bill Chameides, former dean of Duke University's Nicholas School of the Environment. FDA standards regarding personal care products are not as rigorous as its food and drug standards. Additionally, Mr. Chameides reports, neither Canada nor the European Union allow lead acetate to be used in cosmetics. This causes some consumers to avoid the use of products such as Grecian Formula.