You're right that these studies measure the product, not the substance. But TFA is about vaping, and I am referring to that. [edit] Seems that nicotine is not

You're right that these studies measure the product, not the substance. But TFA is about vaping, and I am referring to that. [edit] Seems that nicotine is not really harmless, even in gum or patches: double the risk of heart palpitations and chest pains, 1.67 the risk of nausea and vomiting, 1.5 times the risk of gastrointestinal complaints, and 1.4 times the risk of insomnia. Of course, if you measure anything this closely with >100k participants in RCTs, it's bound to have a significant effect. But these odds ratios are not exactly small. https://link.springer.com/article/10.1186/1617-9625-8-8 https://link.springer.com/article/10.1186/1617-9625-8-8