By effectively freezing facial expressions, Botox could hinder sexual pleasure and the ability to orgasm at all, according to research by Cardiff University. The study, published in Scientific Reports, explored the impact of Botox on embodied emotion, the theory that emotion, and consequently experiences, can be shaped by facial expressions.

Botulinum toxin, otherwise known as Botox, is often used to treat frown lines, and previous research has found this can lead to a reduction in depression. Refinery 29 reports researchers wanted to know if, by impairing the facial expressions associated with sexual excitement, Botox would reduce women’s ability to enjoy sex. The muscle groups often targeted in cosmetic Botox are the same ones associated with sexual excitement and orgasm, including frown and laughter lines, and the area around the jaw.

The researchers followed a small sample of twenty four women who’d had Botox, and were tested before and after treatment, and compared them with twelve women who’d had non-muscle restricting facial procedures, such as skin peels. The women were asked to complete various questionnaires relating to their sexual function, mood and ability to read others’ emotions.

The thirteen women who’d had Botox on their frown lines reported reduced sexual satisfaction, orgasms were harder to achieve and less satisfying. There was also a “near significant” decline among women who’d been treated for crow’s feet and frown lines.

The study concluded that curbing the ability to produce the facial expressions associated with sexual pleasure leads to reduced feelings of sexual pleasure.

The researchers said “This finding demonstrates the importance of facial expressions during sexual intercourse. The results suggest that the facial expressions do not occur simply to communicate pleasure to a partner but they are an integral part of the feeling of pleasure and are important in the process of achieving orgasm. This demonstrates an important role for facial feedback within sexual intercourse and it is potentially a previously unimagined significant negative impact from cosmetic [Botox] treatments.”

The study also examined whether the treatment of crow’s feet (laughter lines) would reduce mood by impairing the ability to smile with the eyes, and whether Botox would curb people’s ability to recognise emotional expressions in others because their ability to mimic emotions would be reduced.

In keeping with the finding on sexual pleasure, the women who’d had Botox on their laughter lines reported increased depression scores, and they were also less likely to be able to recognise others’ emotions.

The researchers said “The current results add to our knowledge of the psychological effects of injections of powerful neurotoxins and broaden the scope of the embodiment of emotions.”