Comment · Fri, August 16, 2013 · Ceretropic
Nefiracetam & Coluracetam
Original post in this thread
Seneframin · 20 points
Those two racetams are the only ones that are rarely discussed on this sub reddit. I would really like some info about them, along with a reason as to why those two racetams are not so used by people ?
What they were answering
alan2102 · 1 points
From wikipedia entry on nefiracetam:
"Studies of long term consumption of nefiracetam in humans and primates have shown it to have no toxicity.[5][6] However, animals which metabolize nefiracetam differently than humans and primates are at risk for renal and testicular[7][8] toxicity. Dogs especially are particularly sensitive, which has been shown to be caused by a specific metabolite, M-18.[9] Higher doses than those in dogs were needed to cause testicular toxicity in rats, although no toxicity was seen in monkeys. Additionally, there has been no evidence of toxicity during clinical trials [5][6]"
u/MisterYouAreSoDumb · Ceretropic
Don't cite Wikipedia. I can go on there right now and change that paragraph to say nefiracetam turns you into a monkey.
The renal toxicity is due to dogs having much lower basal prostaglandin levels than in primates. The lower prostaglandin levels means that nefiracetam's metabolite, M-18, lowered it in dogs to the point of toxicity. Humans will have higher basal prostaglandin levels, so renal toxicity will be LESS likely. That does not mean that there is no risk.
http://www.sciencedirect.com/science/article/pii/S001429990302123X
The TESTICULAR toxicity arise from atrophy of seminiferous tubules in the testicles, with multinucleated-giant-cell formation. This arises after 4 weeks of nefiracetam administration. If you can link me a study showing that humans do not have this issue, please do.
http://www.sciencedirect.com/science/article/pii/S0378427403001978
This study showed that nefiracetam's main metabolite, 5-OHN, increases testosterone 6β-hydroxylase activity in the liver. This proves a mechanism, IN HUMANS, for possible lowering of testosterone levels.
The formation of 5-OHN was significantly correlated with cytochrome P450 (CYP) 3A4-mediated testosterone 6β-hydroxylase activity
Does that mean that it does for sure? No. But it's enough for me to be cautious with my dosages. The mechanism exists for both renal toxicity and testicular toxicity in humans. The fact that it has not been observed yet does not mean we should write off the cautions.