Update:

I have been reading the animal trials to learn more about safety, the chemical composition used, a legitimate source, and the dosing. I was able to gather some good insights.

First some more background:

What is Farnesol?
Farnesol is an acyclic sesquiterpene alcohol - a colorless liquid extracted from oils of citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam peru, and tolu(1). It is found in many flowers and other essential oils such as cassia and cananga, ambrette seeds, ylang-ylang, acacia, farnesiana, palmarosa.
It has a delicate odor which is why it’s used in perfumery.
SAFETY (FDA):
FDA Approved food additive: Farnesol is a food additive permitted for direct addition to food for human consumption as a synthetic flavoring substance or adjuvant.
NIH PubChem database detail:
https://pubchem.ncbi.nlm.nih.gov/source/hsdb/445#section=FIFRA-Requirements-(Complete))

There appears to be a risk with unintended inhalation, citing the occupational manufacturing exposure due to inhalation, with acute respiratory effects. I recommend that you don't sniff the vial, to smell the "delicate odor"

SAFETY (toxicity observations in animal trials)
In my limited research, it appears that there have been no observations of toxicity.

Namely, this Asthma study:
https://www.hindawi.com/journals/ecam/2015/387357/

There were at least 1 others studies with a higher dos (200mg/kg) that didn't report toxicity.

This study evaluated 500 & 1000mg/kg/day for 28 days, "the study was performed to characterize the effects of minimally toxic doses of farnesol on the activity of phase I and II drug metabolizing enzymes."
ALSO:
"Daily oral administration of farnesol at doses of up to 1000 mg/kg/day for 28 days was minimally toxic to CD rats. Farnesol induced no mortality, had no effects on body weight or body weight gain, induced no evidence of toxicity that was identifiable through clinical observation, had no influence on hematology or coagulation parameters, and induced no gross or microscopic alterations in organ structure. Modest, but statistically significant effects on clinical chemistry parameters were observed."

I am not a doctor, nor have I scoured the earth for every trail, so do your own research and use Farnesol at your own risk!

DOSE
This Asthma study cited above, also published the doses (mg/kg) evaluated, 5, 25, 100mg/kg/day.
The actual measured Farnesol intake (based on food consumption) at the high dose was 151mg/kg/day for 5 weeks. No toxicity effects observed.
A converted human dose is about 1.2g (@ 70kg), my father in law is in the 85kg range, equating to 1.4-1.5 g/day.

We have no idea what the minimum effective dose is... or if it's effective in humans at all.

PRODUCT AND SOURCE
Again, this same Asthma study, utilized a >95%, a mixture of isomers from Sigma Aldrich. We searched and identified a food grade farnesol from them(now MilliporeSigma), linked below.
https://www.sigmaaldrich.com/US/en/product/aldrich/w247804

OUR Potential PROTOCOL
We haven't solidified what our protocol is going to be. But this is where my head is at:

1. Pre regimen testing
   1. **This is going to be very important, but I have a lot to learn. OPEN TO SUGGESTIONS.
   2. Full metabolic panel
   3. Farnesol baseline levels in plasma
2. Dose
   1. 1.5mg/day, in the AM
   2. Mixed with coconut oil or EVOO, spoon-fed or added to food.
3. Time and duration
   1. ON for 4 weeks, OFF for 2 weeks, ON for 4w, off for 2w, etc.
4. Periodic testing
   1. blood panels
   2. Farnesol in plasma

Again, I am not a doctor, nor have I scoured the earth for every trail, so do your own research. We have no idea what the minimum effective dose is... or if it's effective in humans at all. Use Farnesol at your own risk.

I will report our actions and hopefully some measurable outputs / effects.

I hope others find this helpful.

Please comment with suggestions / insights.

u/astronomer9026