Today we take a look back in history at an old first-aid antiseptic, Merthiolate (sometimes mistaken for other words like metholiade).
Everyone seems to have a go-to remedy for minor scrapes or cuts. But such remedies have varied over time, from hydrogen peroxide and iodine to rubbing alcohol, adhesive bandages, and over-the-counter ointments.
But treatments like these weren’t so always popular. In fact, there were some treatments that were previously popular but have fallen out of favor in more recent years. Thiomersal is one of those treatments.
But what is thiomersal? If you’re old enough, you might remember it as Merthiolate (or Metholiade). Both it and the related Mercurochrome were common antiseptic treatments in the U.S. during the 1950s and 60s. But whatever happened to it?
The Origins of Thiomersal
Merbromin was a chemical compound developed in the late 19th and early 20th centuries. It consisted of carbon, hydrogen, bromine, mercury, sodium, and oxygen atoms, and was found to have antiseptic properties.
It was eventually marketed as Mercurochrome — an over-the-counter brand that diluted merbromin with water and/or tincture (alcohol) — a treatment for small cuts or open wounds. This product was widely used in the United States in the postwar years, and it was most notable for its sharp sting and tendency to leave red or brown stains on the skin.
Thiomersal was a related, and possibly derivative compound developed by the American pharmaceutical developer Eli Lilly and Company. The compound contained carbon, hydrogen, mercury, sodium, sulfur, and oxygen atoms.
Development into Merthiolate
In 1929, Eli Lilly and Company trademarked thiomersal as Merthiolate. It began to market and sell Merthiolate as an antibacterial treatment, also as a vaccine preservative.
Merthiolate was similar to Mercurochrome in that it was a mercury-based antiseptic treatment that gained popularity in US households during and after World War II. It also stung (some sources say even worse than Mercurochrome) and tended to leave red marks on the skin.
Many Americans of the Baby boomer generation (and earlier) remember Merthiolate as an antiseptic staple of bathroom medicine cabinets. But now, it is virtually unknown to later generations — for a few reasons.
Questions About Safety
The use of Merthiolate came into question in the 1970s. By that time, organic mercury poisoning (like from seafood consumption and environmental waste) was well-known — that it caused damage to the kidneys, brain, and developing fetuses — and made an ethylmercury-based treatment like Merthiolate subject to review.
The United States Food and Drug Administration (FDA) began to review over-the-counter antiseptics in 1978. Over the next decade, Eli Lilly and Company stopped putting thiomersal in its over-the-counter products (ending the practice in the mid-1980s), including the antiseptic Merthiolate.
Nowadays, Merthiolate, and its counterpart Mercurochrome, are more likely to contain the compound Benzalkonium chloride — an ammonium compound — as an active ingredient.
Decline As Antiseptic And Use In Vaccines
In 1998, the FDA ended the “Generally Recognized As Safe” status of thiomersal, due to pharmaceutical companies’ non-submission of corresponding health studies. The FDA also determined that it would subject companies intending to use thiomersal to lengthy review processes.
This may have been the end of thiomersal in over-the-counter Merthiolate, but the compound continued to be used as a vaccine preservative, well into the 1990s, at least in the United States. Thiomersal is still used internationally (though in very small amounts) in many vaccines.
Some believe the use of the compound in vaccines causes autism in infants. In 2011, however, the World Health Organization (WHO) deemed that “there is no evidence to suggest the amount of thiomersal used in vaccines poses a health risk”.
Addressing this controversy, the FDA has suggested both that thiomersal is not harmful in the amounts used in current vaccines, and that the compound is not present in most vaccines recommended for use in the United States. Furthermore, the FDA states the use of thiomersal has “markedly declined due to reformulation and development of new vaccines.”
Though once a wide-spread treatment for small cuts and abrasions, Merthiolate and thiomersal have a greatly-reduced status as over-the-counter antiseptics. However, the pain Merthiolate brought is likely not so easily forgotten.
So if you’re wondering where Merthiolate went, look for members of your generation who remember it, too — they will probably have some pretty powerful memories, to say the least.