> The procedure has not yet been tested on humans and researchers will need to show it is safe to use, particularly if the dye is injected beneath the skin.
How did they resist the urge to sneak a peak at their own arm or one of their fingers?
Rendering transparent rather than covering up would be kind of an anti-cosmetic use.
The reason I mention cosmetics, is it means that it's at least in theory skin-safe for humans up to at least some threshold. The next questions would be: what's the threshold at which it's not skin-safe for us anymore, and is that high enough for this effect to happen? Neither are foregone conclusions though.
Did the article imply you need red light to see the effect though?
Also basic human biology: just because something's safe to consume (which keeps it isolated from the rest of your body until it's been through the digestive tract) in extremely low doses doesn't mean it's safe to expose yourself to a highly concentrated dose via external exposure.
That doesn’t always follow. There are (organic, large-molecule) substances that your mucus membranes will protect you from, and which you’ll then digest (denature) and greatly metabolize (non-leaky intestinal absorption routes through the liver) and so render harmless; but which would greatly harm you if left on your skin, as the substance can potentially absorb from there all the way to your bloodstream, without any digestion or a chance at first-pass metabolism.
Think, for example: testosterone gel. Eating it wouldn’t result in much if any testosterone entering your bloodstream — but rubbing it on yourself sure does.
> While re-synthesizing LSD, he accidentally absorbed a small amount of the drug and discovered its powerful effects
How else do you learn?
Still do at times, but it's much harder to get the good stuff, like KNO3.