Badly fitting condoms are not only likely to split and break, but they may also reduce sexual pleasure for both partners, suggests a study published in the journal Sexually Transmitted Infections.
The researchers base their findings on 436 men between the ages of 18 and 67, all of whom were recruited via newspaper ads and a blog on the website of a condom sales company.
The men completed a questionnaire on the Kinsey Institute for Research in Sex, Gender, and Reproduction website about the fit of condom they had most recently used for penetrative sex with a female partner.
Almost half the participants (just under 45%) said that they had used a badly fitting condom when they had last had sex during the previous three months.
They were more than 2.5 times as likely to report breakage or slippage as those whose condoms were a good fit, and five times as likely to report penile irritation.
They were around twice as likely to say that the poorly fitting condom made it difficult for them and/or their partner to reach orgasm and that this curbed sexual pleasure for both parties.
They were also around twice as likely to say that their poorly fitting condom interfered with getting and maintaining an erection. And they were twice as likely to say they removed the condom before sex had ended.
The authors acknowledge that their study, which is the first of its kind to look at the impact of poorly fitting condoms on sexual functioning, is limited by its reliance on self report. Nevertheless, they say that the findings "emphasise the point that men and their female sex partners may benefit from public health efforts designed to promote the improved fit of condoms."
An accompanying podcast, featuring co-author Dr Bill Yarber, explains that the prospect of reduced pleasure and intimacy could put people off using condoms.
Dr Yarber voices concerns that pornography may distort body image, and emphasises the care needed in any public health or marketing campaigns to address the issue. Men won't buy condoms labelled as "small" or "extra small," he warns.