Why the Nicotine Delivery of a Cigarette Can Vary

If you smoke for a long enough time, you may remember a period of time when tobacco companies could label their products with "light colors" to indicate that the tar or nicotine content of the cigarettes was low. Low yield cigarettes still exist, but one of the reasons why cigarette manufacturers are no longer allowed to use "light" labels is that these types of cigarettes often work differently in practice than in clinical trials.
Low production cigarettes have perforated filters, which is one of the biggest reasons why many public health officials believe that the term "light" is deceptive. When you smoke with a perforated filter, the perforation should dilute the smoke by introducing fresh air into the mixture. When analyzing cigarettes using a smoking machine, perforations will work as expected. However, in practice, perforation usually does not work because human smokers cover the perforation with their fingers.
This phenomenon was explained in a study published in the International Journal of Environmental Research and Public Health in 2020. The researchers conducting this study examined the smoking patterns of five individuals and found that they inhaled five times more smoke than measured by smoking machines. Among these five smokers, although they all smoke the same brand of cigarettes, the average amount inhaled per cigarette ranges from 495 to 2127 milliliters.
Considering all this information, you can see that there is almost no reason to check the nicotine content in a particular brand of cigarettes, as the results in real life are completely different from those in smoking machines. You will eventually feel frustrated because the amount of smoke you inhale from cigarettes may be much higher than what is measured in the laboratory.
For electronic cigarettes, the nicotine content is relatively standard, including 0%, 1%, 2%, 3%, 5%, etc. Basically constant.