This article is copyright © Nils Osmar 2019.
Some people are convinced that sublingual NMN tablets are superior to the oral kind that you swallow in a capsule.
I respect their opinion and wish them well. But the studies I’ve read suggest that the non-sublingual delivery method, which passes through the gut en route to absorption, is more likely to result in the NAD generated by the body when we take NMN, being absorbed and utilized by the body.
The point being that NMN is a precursor, which (we hope) will result in the creation of more NAD in our bodies. The point isn’t to get more NMN into our bloodstream, but more NAD into our cells.
When we take NMN sublingually, we are bypassing a carrier which is found in the gut — a membrane protein called Slc12a8 — which is involved in transporting NAD through our cell membranes. (Some have speculated that this enzyme exists to help us absorb the minute quantities of NMN found in food.) The amount of Slc12a8 actually increases in the gut as we age, possibly because the body is producing less NAD. See this study.
This suggests that bypassing the gut and taking NMN sublingually may result in less, not more, NAD getting into our cells.
It’s also worth noting that all of the animal studies showing benefits of taking NMN were done by putting NMN in the lab animals’ drinking water, not shoving a little under their tongues and waiting for it to be absorbed.
I’m not saying that it’s impossible that there could be benefits to taking it sublingually — just that those benefits, if they exist, have not been established by scientific research yet. Time and more studies will tell.
See also: How Much NMN Should People Take?
PERSONAL NOTE: I take NMN in capsule form for the reasons listed above. But I’m not ruling out the possibility that sublingual delivery may have benefits that we’re not aware of yet.
I am planning an N=1 experiment to see whether mixing it a little dollop of coconut oil and putting it under my tongue, affects me any differently. If I notice anything different when taking it that way, I’ll post the information here.