Caffeine is a natural blood thinner so it could have some interesting effects for them. Not sure what though.
They’d probably also jitter quite a bit, depending on whether or not they absorb things more readily through their food (which one would think they would due to needing to absorb the things they need from blood) which could make the risk of addiction fairly substantial.
So yea, I think it would, though how that plays out is up to you and your worldbuilding 🙂
Unwanted butting-in from medical human and caffeine addict: caffeine isn’t so much a blood thinner, but it does act to boost metabolism and acts to release adrenaline (small doses). Obviously the specific effect will vary based on your vamp mythos and what you’ve decided vampirism means in your story, but I can see this used in an interesting way or two…
For instance, if your ‘verse uses cold vamps (ie room-temperature or slightly above), caffeine and a few other substances could act to help them raise their body temperature to “pass” with a human date (other things being alcohol for the vasodilatory properties, cinnamon for metabolic boost, taurine/guanine, plus the strategic application of hot packs). NICUs will give underdeveloped premies caffeine drips to aid development and raise core temp, so this isn’t completely left-field.
It also increases heart rate (particularly in “overdose”), which, if you have still-beating-heart-just-super-slow-heart-rate vamps, they might use caffeine to take their heart rate from “almost a stone” to “a very very very slow, but marginally realistic, human heart rate”. Again, passing for human on a date…
Just remember, caffeine is also a diuretic, and they may need to use the bathroom. And a male/bepenised vamp in the bathroom pissing blood into a urinal just tickles me pink.
Other thoughts: if vampires eat blood, and digest blood, then their poop will look very dark and tarry, and stink like the ending of worlds, and their puke will look like coffee grounds. Just a word to the wise.
Note to Scripty-Followers: @thebibliosphere‘s blog is SO VERY MUCH NSFW. I love her, but do not say I did not warn. Gods alone, so very NSFW…
I will have you know I only posted twice about sex related things yesterday. (Multiple reblogs of the same post don’t count, I was helping people with their vampire erotica problems, I should be sainted for my restraint)
and “caffeine isn’t so much a blood thinner”, my doctors lied to me, bitches gonna get stitches. Thank you for that about the heart rate and the body temp, I’ll be using that.
I-want-my-IWTV 