Objective: The purpose of this study was to compare the passive permeation across human skin of magnesium (Mg) from pharmaceutical grade Mg chloride (MgCl2) formulated in cream to that of pharmaceutical grade MgCl2 in solution. Material and methods: The permeation was performed using human cadaver skin (Pelfreez, USA). The skin was soaked in the receptor medium (phosphate buffer saline 7.4) to equilibrate and then cut into appropriate size for the study. The transdermal Diffusion Cell Drive Console (Logan System FDC-6) was used to study the permeation. The transdermal permeation efficiency of Mg from MgCl2 cream I and MgCl2cream II was studied across skin compared to positive control MgCl2 solution and negative control phosphate buffer solution. The cream or MgCl2 solution equivalent to 2.76 mg of Mg were applied per 2.52 cm2 of skin and mounted on diffusion cell. Samples were collected after 1, 2, 3, 4, 5 and 24 h and analyzed using atomic absorption spectroscopy at 285 nm. The experiments were performed in triplicates. The results were analyzed using unpaired t-test. Results: The cumulative Mg permeation from Mg cream I, Mg cream II, MgCl2 solution, and phosphate buffer across human skin after 24 h were found to be 29.79 ± 13.92, 24.53 ± 9.98, 6.18 ± 1.36, and 5.62 ± 1.83 μg/2.52 cm2 respectively. Both creams showed statistically significant (p<0.05) Mg permeation compared with the two control solutions; Mg cream I showed greater Mg permeation than Mg cream II, but the difference was not statistically significant. The MgCl2 solution showed a similar result to that of phosphate buffer. Conclusion: A formulated Mg cream was able to successfully deliver the Mg of pharmaceutical grade MgCl2 across human skin. Transdermal Mg may play an important role treating symptoms of sub-optimal Mg status. However, further in vitro and animal studies are warranted to establish the efficacy of formulations.