[Lotus]

Amino Acid Composition, Molecular Weight Distribution and Gel Electrophoresis of Walnut (Juglans regia L.)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3958834/

The results of size exclusion chromatogram indicated molecular weight of the major components of walnut proteins were between 3.54 and 81.76 kDa.

Meaning, the molecular weight of walnut oil is 3.54 g/mol, making it the lowest skin penetrating oil that i've seen.

As example " puerarin " is 343.5 g/mol and miroestrol @ 520.183 g/mol (bigger molecules vs. 3.53 g/mol of walnut oil). 

molecular weight (MW) of a compound must be under 500 Dalton to allow skin absorption. Larger molecules cannot pass the corneal layer....according to the  “500 Dalton rule”. 

A new miroestrol glycoside from the roots of Pueraria mirifica
https://www.researchgate.net/publication...a_mirifica