I have taken LE's Super Bio-Curcumin for over half a decade now, & haven't had any libido issues. I'm 62, so I expect I'd notice at this age. A 30 day trial might be helpful to see if it effects you adversely.
People used to eat a lot of eggs until they were demonized for the cholesterol content. Dietary cholesterol doesn't affect serum cholesterol all that much, but apparently that didn't matter.
Interestingly, choline didn't used to be classified as an essential nutrient, but once eggs fell out of favor, this was reconsidered in 1997/98, and an RDA was set.
https://www.ncbi.nlm...les/PMC2782876/
Deficiency symptoms include: "Impaired fat metabolism & transport" fatigue, & #14 here
http://www.healthsup...de.com/choline/
reads: "as choline is critical for brain function and intake decreases with age, deficiency might lead to impaired memory or brain function or senile dementia (shortage of acetylcholine in the brain has been associated with Alzheimer’s disease)"
Your possible brain fog connection? Regarding the ACH, lecithin should support this (better ACH levels), but I haven't seen any evidence an excess of lecithin might cause problems with overproduction of ACH.
A 30 day trial to see if this might help shouldn't be risky, & might prove enlightening.