Eau de Homme

A Novel Investigation into Human Pheromones (Part 2)

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Our first trial (Part 1) was the first scientific study on the efficacy of vabbing, or the use of vaginal fluid as perfume to attract men. We observed that men stood closer to women who had vabbed, and that their heart rates increased significantly after hugging her. 

Upon hearing about the results of this trial, Shahid wanted to know: Is there a male equivalent? Do men have potential love potions hidden in their bodies?

So we tested it. Yes, it is what you think.

Many thanks to our patron Shahid for supporting this novel research.

Note of clarification

We’re not pretending to be a university research lab. We understand that this experiment doesn’t meet every gold standard of academia. Our objective is to study something that has never been studied before, to go a level beyond anecdotal evidence and bring the scientific method to a new question.

Cosimo’s approach to science is about balancing a dedication to rigor with the courage to proceed and experiment. We can and should apply scientific truth-seeking methods to more unexplored questions, even in the absence of ideal conditions, with transparency in how we communicate results.

How we chose the substances

Compared to the innovative techniques used by the vabbing community, men haven’t gotten as creative with their attraction methods. Based on our projected sample size, we decided to test two potential male substances versus a control substance.

In order to choose the most probable sources of male pheromones, we executed a review of the existing research based on the following questions:

  • What is the existing evidence that human males secrete pheromones that attract females?
  • Where do these pheromones come from?
  • What are the best studies that have been done on this topic? Are they good quality studies?
  • As a man, if I wanted to try to extract pheromones, where in my body could I possibly get it from, and would it successfully attract females? 

Our full literature review can be viewed here. From this, we concluded that the most studied source of potential pheromone production is in the apocrine glands, primarily located in the armpit and pubic regions. Besides that, there aren’t many known contenders.

Based on this assessment of the literature, we selected apocrine gland sweat and seminal fluid as the substances to test (aka ball sweat and semen).

How we tested it

Experiment Design

The experiment was a similar format to the vabbing experiment. In each interaction, the female participant hugs a male who had applied one of the three treatments as perfume. After a 10 second hug, she steps away and answers a series of cognitive questions. 

We had 13 participants (9 male and 4 female) who were randomly mixed and matched to make 27 different male/female pairings. Each pairing was randomly assigned one of the three treatments – semen, ball sweat, or control substance. So in total, each substance was tested 9 times by a random pairing of a male and a female. We ensured that males and females who were well-acquainted were not paired.

Everyone gave their informed consent, and the females were also informed that they would be olfactorily exposed to either seminal fluid, apocrine sweat, or a control substance. However, they did not know which substance they were being exposed to in each interaction, and they were unaware of the key measurement outcome – the social distance, or how far apart they stood after hugging.


The males were asked to provide a fresh sample of their own semen from within a few hours before the experiment. The experiment was conducted in the morning, so they were able to arrive with fresh samples. The apocrine sweat was collected at time of use. 

The control substance was a simple mixture of bleach and water, which believe it or not smells a lot like semen, since semen is slightly alkaline and has a similar pH to our bleach-water mixture. We pretested the control substance and confirmed with several people that it smelled like semen. Since bleach is not safe to put on skin, we placed it on a sponge in an open tube which was worn as a necklace underneath the participant’s shirt.

Before each interaction, males were prepared in a separate room with an assistant who explained how to apply the treatment. Semen and sweat were applied to the side of the neck (as in the vabbing experiment), and the control substance was worn as a backwards necklace on the upper back. After each interaction they thoroughly cleaned the neck with soap and water.


There was a hidden ruler against the floor which we used to secretly measure the distance at which the female stood from the male – this was the main outcome of interest, same as in the vabbing study. We also measured heart rates before and after the hug, responses to the cognitive questions, and response times.


We thought this trial would be fun and silly, but we did not anticipate observing a significant effect from the male perfumes. To our surprise, females stood about 4 inches closer to males who were wearing either apocrine sweat (p=0.0109) or semen (p=0.0682) compared to the control substance. The sweat group stood 4.5 inches closer and the semen group stood 3.8 inches closer on average. This is about the same effect size as vabbing!

There was greater variability in the social distance of the semen group than the sweat group, which was more consistently closer.

The other outcomes, heart rate and cognitive test performance, were not affected. 

Alternative analysis for statistics nerds

As mentioned in Part 1, the p-values from a t-test are not the singular best measure of evidence about a hypothesis. We can also consider the effect size, indicated by Cohen’s d, and the relative evidence of each hypothesis, quantified by the Bayes Factor (see Dienes 2014).

The Cohen’s d for sweat and semen are -1.2 and -0.76 respectively. These are fairly large effects, particularly the effect of sweat, which is 1.2 standard deviations. 

The Bayes Factors are 6.1 for sweat and 1.8 for semen. Again, the evidence is stronger for sweat, meaning that the data are 6.1x more likely under the alternative (women stand closer with sweat) than the null (sweat makes no difference). 

Does this mean I should put ball sweat on my neck before going out?

The study has some limitations. The sample size was small, the treatments were not completely blinded, and not all possible confounders could be accounted for (e.g. subconscious signaling from the males, natural level of attraction between participants). Despite our efforts to replicate natural conditions, it still does not perfectly mirror a real-world setting.

Still, the results suggest that females stand closer to males who have fresh ball sweat applied to their neck! While the evidence for semen is less strong, it also indicates that semen is attractive. It makes more sense for the sweat to be attractive since semen suggests a male who has already engaged in sexual activity, which might signal reduced immediate sexual availability, whereas sweat can be an indicator of physical activity, fitness, and immediate readiness.

The results are not conclusive, but they are enough to warrant further research. Future studies could investigate how these substances interact with other sensory cues, how menstrual cycle affects females' response, or how these natural perfumes compare to colognes.

We're not going to tell you what to do, but if you do try out these perfumes, let us know how it works out for you.

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