Ad description

An ad for Numan, a website providing treatment for men’s health issues, seen on the side of a bus in March 2019, stated "Does cycling affect you in the bedroom?". Further text stated "Numan" and smaller text underneath stated "#bookoferections".


The complainant challenged whether the implied claim that cycling could have a negative effect on erectile performance was misleading and could be substantiated.


Vir Health Ltd t/a Numan said that the claim was backed up by scientific research. They said that several studies had suggested a causal link between cycling more than 3 hours a day and erectile dysfunction. While further research was required, the National Institute for Health and Care Excellence (NICE) had added advice to stop or cut back on cycling to their guidelines on treating erectile dysfunction. That advice was being taken by a large proportion of UK based doctors. They provided a link to a scientific study.



The ad stated "Does cycling affect you in the bedroom?". The ASA considered that consumers would understand that to mean that cycling had a negative impact on erectile performance. Therefore, men who saw the ad were likely to understand that cycling could lead to them developing erectile dysfunction problems, or could be the cause of their existing problems. We examined the evidence provided by Numan.

A randomised cross-sectional study of 1,709 men aged 40‒70 years included those who habitually undertook a range of different cycling activities at different levels and durations, as well as men who did not cycle. Participants were surveyed about their physical and sexual activities, including nine questions directly related to erectile dysfunction, and were categorised as having either none/minimal erectile dysfunction or moderate/complete erectile dysfunction. The study found that cycling less than 3 hours per week was not associated with erectile dysfunction, and may be a protective factor against it. At the same time, it found a higher prevalence of erectile dysfunction among men who cycled 3 or more hours per week, compared to moderate cyclists and non-cyclists. However, the authors acknowledged that the population was not of sufficient statistical power to establish a causal link. Furthermore, while the study controlled for a range of possible confounding factors, health conditions were based on self-reporting rather than clinical diagnosis or reference to medical records, which was a potential limitation.

We noted that the NICE Clinical Knowledge Summary on erectile dysfunction listed long-distance cycling as a possible risk factor. It also advised that men who cycled for more than 3 hours per week should be encouraged to trial a period without cycling to see if it improved their problem, or take preventative measures such a properly fitted seat. However, the guidance acknowledged that more research was needed to confirm whether cycling was a risk factor for erectile dysfunction, and referred to a systematic review which reported that no sufficient evidence existed to either attribute or refute a causal relationship between cycling and erectile dysfunction.

We considered that we had not seen sufficient evidence to substantiate the claim as consumers were likely to understand it and therefore concluded that the ad was misleading.

The ad breached CAP Code (Edition 12) rules 3.1 (Misleading advertising) and 3.7 (Substantiation).


The ad must not appear again in the form complained about. We told Vir Health Ltd t/a Numan not to state or imply that cycling had a negative effect on erectile performance, unless they held sufficient evidence to substantiate their claim.

CAP Code (Edition 12)

3.1     3.7    

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