•Energy efficiency was measured by using Super-SBM model with undesirable outputs.•Energy endowment has a significant negative impact on energy efficiency.•Direct impacts of environmental regulations on energy efficiency were analyzed.•The moderating effect of various environmental regulations was diverse. Achieving carbon neutrality requires low-carbon energy transformation and further a pronounced enhancement of energy efficiency and environmental regulation. However, the impact of energy endowment on energy efficiency and the moderating effects of various environmental regulations have not yet been studied in an integrated framework. This paper aims to address this knowledge gap by employing a system generalized method of moments (system GMM) for China with panel data of 30 provincial regions from 2008 to 2018. The results reveal varying energy efficiency among different provincial regions in China at a medium-to-low level and confirm the existence of resource curse at the national level since the impact of energy endowment on energy efficiency is significantly negative. Whereas market-based environmental regulations had a significantly positive moderating effect on the relationship between energy endowment and energy efficiency, this effect was insignificant for command-and-control environmental regulations. These findings provide empirical evidence to support the formulation of environmental regulations that will further improve energy efficiency and carbon neutrality in China.