Actress Zooey Deschanel has signed to front a campaign for Pantene shampoo even though the active ingredient was developed by Hoffman-LaRoche, which has been linked to the recent massacre in Afganistan.

The Swiss pharmaceutical giant is entangled in the murder investigation of civilians in Afganistan by Army sergeant Robert Bales through its drug mefloquine.

Also known as Lariam, the anti-malarial drug is believed to enduce psychosis and extreme depression leading, in some cases, to suicide. Bales is suspected to have been using the drug when he carried out the massacre of 15 Afgan civilians.

When Bales was in Iraq in 2010, he sustained a massive brain injury. If he was taking the drug, its side effects would have been more pronounced, according to some medical experts. Soldiers who have suffered traumatic brain injuries are particularly advised against using it.

The drug’s dangers were known as far back as 2004, when United Press International found that six elite Army Special Forces soldiers were on mefloquine when they committed suicide. But Hoffman-LaRoche continues to manufacture and sell the drug.

The Pentagon refuses to confirm or deny whether Bales was given mefloquine, according to Mark Benjamin, an investigative reporter writing for the Huffington Post.

In 2009, the U.S.Army limited the use of the drug, although it is still dispensed in Afganistan.

Hoffman-LaRoche was involved in a similar controversy in the 1990s over its drug Accutane, which is used to treat acute acne. It was found to cause severe depression. Several teens using the drug committed suicide, and the company was hit with several wrongful death suits.

The risks of depression were first reported in 1985, yet the company continues to make the acne drug.

Procter & Gamble, the giant U.S. consumer products company, acquired pantene products in 1985 and hired Deschanel. Pantene’s active ingredient, panthenol, a derivative of Vitamin B5, is not known to cause side effects, although some reports say it’s useless in shampoo.

“I am so excited to be a part of the Pantene family. I’m really into hair! So, I just like hair, so… that sounded weird,” said the 32-year-old actress at a media event.

Calling her a “breath of fresh air for the brand,” Kevin Crociata, Marketing Director of North American Hair Care at Procter & Gamble said Deschanel “perfectly fits the fun side of Pantene.”

It’s unlikely Deschanel is even aware of her sponsor’s connection to the Hoffman-LaRoche controversy.

But socially conscious celebrities, as she claims to be, should be careful about the products they endorse. She follows Pantene campaigns by Naomi Watts and Eva Mendes.

Check out her video below.