According to the cigarette boxes, nicotine levels per analog that I have seen vary from about 0.1mg (for the "lightest" ultra light) to about 1.5mg (for a full strength cig). There are regional variations, depending on local legislation. The trend in many countries has been for nicotine levels to be reduced over the years, which if you are anything like me, made you want to smoke more..
This is not the level of nicotine in a cigarette, but it is the level that has been tested using a standardised procedure using a "smoking machine" which simulates a person smoking. The nicotine delivery is IMO different on an e-cig compared to a cigarette, possibly because of additives to the tobacco like ammonia which is said to increase the effect of the nicotine and produce more of a "rush" (to do with increasing the amount of freebase nicotine delivered by smoking).
I found an interesting preliminary study by one company on the nicotine absorption levels of e-cigs compared to cigarettes and patches which you might want to have a look at.
http://www.intellicig.com/images/im...od Nicotine Concentration from Intellicig.pdf
I agree with Don - experimenting with different levels is the best way. Smokers (and e-cig users) are able to self regulate their intake IMO. As a rule of thumb, I would say if you were a lighter smoker, you are unlikely to need the high strength liquids (levels above 18mg/ml really). But everyone seems to be different here.
] Much more important than reducing (or even maintaining) your nicotine ingestion is avoiding all that other gunk in analogs.
