Abstract Despite recent technological advances in horizontal drilling and hydraulic fracturing, primary production from unconventional oil reservoirs is usually less than 10 percent of the original oil in place. This low recovery has made it essential for operators to test methods that aim to improve recovery efficiency and recover incremental oil from existing wells. One of such methods is the use of solvents for improved recovery in shale oil reservoirs via cyclic gas injection also referred to as a "huff-n-puff" process. Previous laboratory studies have demonstrated promising results on unpreserved shale core plugs using CO2, N2 and C1 as solvents, however, none have shown recovery results using ethane or higher molecular weight gases for cyclic gas injection. This paper presents improved oil recovery results from cyclic gas injection experiments using C2 and n-C5 in comparison to N2 on unpreserved Eagle Ford crushed samples and core plugs with n-C12 as the oil phase. Core plugs and crushed preserved shale samples were vacuum dried and then re-saturated with n-C12 at 6000 psi for 48 hours, then huff-n-puff experiments were conducted using n-C5, C2 and N2. Recovery factors obtained using n-C5 at injection pressures of 2000 psi and 5000 psi showed that oil recovery increased with an increase in surface area to volume ratio. For the same surface area to volume ratio, oil recovery is higher at higher injection pressures. A comparison of recovery factors between C2 and n-C5 show that C2 was more effective than n-C5 because it showed higher recovery factors at 2000 psi and 5000 psi injection pressure. NMR T2 distributions also showed that C2 was able to recover more oil from the small and intermediate pore sizes without leaving behind any residual fluid in the small pores unlike n-C5. The higher recovery factors obtained for C2 are a result of its lower viscosity and because it is able to expel more oil out of the shale pore space as it flashes to gas upon depressurization compared to n-C5. Comparing N2 recovery results to both C2 and n-C5 at 5000 psi injection pressure demonstrated that N2 yielded the lowest recovery factors because it is essentially immiscible with the oil. These experimental results can be used as the basis for scaling up to field scale huff-n-puff gas injection pilots.