CBD: Bioavailability and Administration

Apologies in advance to the spam filters for this sub, because whenever I post anything about CBD on Reddit it always attracts shillbots en masse.

There's a lot of hype about CBD, and underpinning it is some genuinely useful science. You've probably already heard a lot about its more common benefits and how it can be used in conjunction with other PEDs, so I'm not going to go over too many of the more common ones as others have already done a better job than I could. In short, it's an interesting compound with many health applications. Perhaps its most beneficial for our purposes is as a sleep aid, and general anxiolytic. Now, onto the science!


Bioavailability and half life

As with most compounds, nothing beats injectible for bioavailability, with inhalation and sublingual coming in behind, followed by oral. There's a little bit of conflicting information on that last point in the studies that I found:

- 6% oral bioavailability: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189631/

- 13-19% oral bioavailability: https://sci-hub.tw/https://accp1.onlinelibrary.wiley.com/doi/abs/10.1002/j.1552-4604.2002.tb05998.x?sid=nlm%3Apubmed

- 6-20% THC oral, up to 80% vape CBD https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4718604/


The half life is dictated by its method of administration:

- 18-32 hours orally: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707667/

- 9 hours IV: https://sci-hub.tw/https://accp1.onlinelibrary.wiley.com/doi/abs/10.1002/


Many people make a vapeable version of it, for which the following information may be useful:

- MCT oil + vegetable glycerin is likely to be the safest carrier, as propylene glycol and polyethylene glycol 400 have potentially unsafe levels of formaldehyde when vaped https://sci-hub.tw/https://www.liebertpub.com/doi/abs/10.1089/acm.2016.0337

- However, VG can cause stiffness in the soft coverings of lungs https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3127174/


For those brave enough to make an injectible version, /u/MezDez was kind enough to share his experience:

2% benzyl alcohol

10% benzyl benzoate

Remainder ethyl oleate at 100mg/ml.

0.5ml insulin syringe, measure out 0.05ml (5mg) and take this subQ.


Brain health

It appears to be restorative and neuroprotective in a rat model: https://www.sciencedirect.com/science/article/pii/S0028390812002328?via%3Dihub

Even better, it was studied in adult humans here, also showing neurogenesis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4543605/

Also of interest, hippocampal pathology can be found here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5908414/


Appetite supression

I left this for last because this is not an effect that I have personally noticed from it, but YMMV - it's an interesting potential application that I happened across: https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1038/sj.bjp.0706157


Other articles

/u/mrhappyoz was kind enough to provide this link of other studies on CBD and related compounds: https://pastebin.com/uWLmU3Sz

https://www.reddit.com/r/PEDsR/comments/bxeghx/cbd_bioavailability_and_administration/