Q: After having sex for first time, why does one's body change so significantly? (example like smell, period length, etc)
A: While sex can create temporary changes in one’s body, such as increased blood flow and estrogen levels (for women) or testosterone levels (for men), there are no long-term changes that the body goes through after having sex for the first time. There is actually no observable way to tell if someone is a virgin or not. It used to be thought that a woman’s hymen would tear when she had sex for the first time, but we now know that many women lose their hymen well before they ever have sex (it begins to naturally deteriorate when beginning puberty) and that some women’s hymen doesn’t tear at all from having sex. In other words, having sex for the first time or any time doesn’t produce any lasting or noticeable changes in the body.
It’s likely that if you noticed any changes in yourself, this is probably due to “illusory correlation,” which is when people expect a relationship between two events (such as having sex and seeing resulting changes in their body) and so become hyper-focused on finding any evidence for this relationship. This is similar to a placebo effect. For example, if you took a pill that you thought would make you drowsy, it’s like you would start to notice yourself becoming drowsy, even if the pill didn’t actually contain any medication at all. If you took the same pill, but expected it to make you anxious, you would probably find yourself suddenly becoming more anxious. We often see or experience things simply because we expect to.
Answers provided by Dr. Ross Avilla
Dr. Ross Avilla has been teaching Human Sexuality since 2013 and has a PhD in psychology from UC Davis. Dr. Avilla is not a clinician and all information and advice offered on this website is for educational purposes only.