In April 2019 Ethical Consumer viewed Pfizer's website, www.pfizer.com, and found that the company tested its products on animals.

It stated "Pfizer is ethically and legally obliged to rigorously evaluate potential new medicines and therapies. Many of these evaluations can be, and are, accomplished by techniques that do not require the use of animals. However, given the present state of scientific knowledge, testing potential new medicines and therapies in animals is frequently critical to their evaluation, and is required by regulatory authorities worldwide to ensure the quality, efficacy and safety of the medicines we discover."

In April 2019 Ethical Consumer viewed The Horse Fund's website, www.horsefund.org, which had a factsheet on Premarin - a drug manufactured by Wyeth who merged in 2009 with Pfizer.

Premarin, is derived from pregnant mare's urine (PMU). According to the factsheet PMU was one of the most widely prescribed drugs for hormone replacement therapy (HRT) which is given to women experiencing menopausal symptoms.

In order to create this drug, mares were often keep confined, pregnant and milked for their urine. It was reported that often their stalls were so small they could not turn around and they were forced to wear rubber urine-collection bags at all times causing chafing and lesions. Drinking water was often restricted to get urine with a higher yield of concenrtrated estrogen. Once the foal was born the mares were re-impregnated. Foals were seen as a by-product of the industry and they were often sold to slaughterhouses.

As a result Pfizer was marked down in the factory farming and animal rights categories.