ABSTRACT Admin Supplement: Proj 2 Addictive Threshold of Nicotine and the Impact of Sweeteners This Administrative Supplement is a request to support an unexpected increase in costs related to Project 2. The specific aims of this study will determine the threshold doses of nicotine for reinforcement, discrimination, and subjective-rewarding effects individuals who smoke and whether these threshold doses change with an inhaled sweetener (sucralose) in dependent and non-dependent smokers, as well as with an inhaled sweetener (sucralose) delivered via e-cigarettes concurrent with IV nicotine infusions. The project requires the use of sterile intravenous nicotine solution. Following an FDA audit, the compounding pharmacy that supplies the nicotine solution for this project (USSF) has instituted new practices and safeguards which have led to a significant increase in the cost of IV nicotine solution from the original quote in included in our Project 2 budget proposal. Project 2 depends on the availability of sterile nicotine vials that allow the administration of nicotine intravenously. This supplement will allow us to continue this research without interruption. The findings of this study are expected to guide the FDA in setting science-based benchmarks for reducing the risks from tobacco products.