A cursory search yielded these:
"It is a common misconception that dark lips are an indication of bad health and are an unnatural state of the skin and mucosa. Lips darken over a period of time naturally, and therefore it just might be a genetic destiny. In fact, you just might have a family history of it. The lips are similar to any other skin on your body and contain the skin pigment melanin. There are many triggers over the course of one's life that causes excess melanin production from the presence of androgen to excess insulin in the blood. Therefore, it might make sense to see a doctor or a dermatologist to be absolutely sure."
And how about that one going around about lipstick containing lead which can be detected by a gold ring?
The bottom line is that U.S. medical literature has yet to record a single case of anyone's coming down with lead poisoning through lipstick use. (And, in any case, contrary to what is claimed in the alarming e-mail..., contracting cancer is not one of the recorded adverse health effects one is likely to suffer through excessive exposure to lead.)
With the abundance of beauty products out there, it pays to be careful. At the same time, it is also prudent to be savvy.