Correctol was pulled from shelves because its active ingredient, phenolphthalein, was linked to cancer in animal studies. In 1999, the FDA issued a final rule declaring phenolphthalein “not generally recognized as safe and effective,” effectively banning it from over-the-counter laxatives sold in the United States.
What Phenolphthalein Was and Why It Raised Alarms
Phenolphthalein was a stimulant laxative used in Correctol and several other popular brands for decades. It worked by irritating the lining of the intestines to trigger bowel movements. For most of its history, the FDA classified it as Category I, meaning it was considered safe and effective for over-the-counter use.
That changed in the mid-1990s when studies conducted by the National Toxicology Program revealed serious problems. When fed to mice and rats, phenolphthalein caused tumors at multiple sites in the body. Mice of both sexes developed thymic lymphoma, a cancer of the immune system, along with connective-tissue tumors. Female mice developed ovarian tumors and higher rates of malignant lymphoma overall. Rats developed tumors of the adrenal gland, and male rats developed kidney tumors.
Beyond the cancer findings, phenolphthalein was shown to be genotoxic, meaning it damaged DNA itself. In one study using mice with a partially disabled tumor-suppressor gene (a gene that normally helps prevent cancer), dietary phenolphthalein caused measurable chromosomal damage and malignant thymic lymphoma in just 26 weeks. The FDA concluded that chronic use “could lead to damage to the human genome” and “could increase the risk of malignancy.”
The FDA’s Regulatory Timeline
The FDA moved in two stages. In September 1997, the agency published a proposed rule to reclassify phenolphthalein from Category I (safe and effective) to Category II (not safe and effective). This was essentially a public warning to the industry: reformulate or stop selling. On January 29, 1999, the final rule took effect, officially declaring any drug product containing phenolphthalein to be misbranded. Products without a new drug application, which included all over-the-counter laxatives, became subject to regulatory action.
By the time that final rule was published, most manufacturers had already gotten the message. The FDA noted that the majority of companies had either reformulated their products, were in the process of doing so, or had stopped selling phenolphthalein-containing laxatives entirely. Correctol’s manufacturer reformulated the product with bisacodyl, a different stimulant laxative, for a time before the brand eventually disappeared from store shelves altogether.
How Bisacodyl Compared to Phenolphthalein
The replacement ingredient, bisacodyl, was put through the same types of safety testing that had flagged phenolphthalein. The results were starkly different. In studies using the same genetically susceptible mice, bisacodyl produced no drug-related tumors, no chromosomal damage, and no cell transformation in lab assays designed to detect cancer-causing potential. The side effects researchers observed with bisacodyl were limited to what you’d expect from a laxative: diarrhea, soft stools, and some thinning at extremely high doses. No tissue damage was found on examination.
Phenolphthalein, by contrast, was “unequivocally genotoxic” in the same models, regardless of how it was administered. It reduced survival in both male and female mice, with early deaths attributed to thymic lymphoma. It also showed potential to promote lung cancer development when combined with other carcinogens in transgenic mice. The safety gap between the two compounds was not subtle.
Is Correctol Still Available?
The Correctol brand appears to have been discontinued entirely. Searches at major retailers return no results for Correctol-branded products. The brand went through a transitional period after the phenolphthalein ban, selling a bisacodyl version and later a stool softener formulation, but neither version maintained enough market presence to survive. If you previously relied on Correctol, the same active ingredients it used in its later formulations (bisacodyl and docusate sodium) are widely available under other brand names and as generics.
The phenolphthalein version, however, is gone for good. The ingredient remains classified as “reasonably anticipated to be a human carcinogen” in the National Toxicology Program’s Report on Carcinogens, and no manufacturer has pursued the new drug application that would be required to bring it back to market.