Why isn't Centella Asiatica (Gotu Kola) getting more attention?

Listen, I get it. You did have a point underneath the emotional response that didn't go unnoticed. You think it is hypocritical to use animal studies to say something may provide a benefit, while not using an animal study to warn of a possible side effect. On the surface that sounds reasonable. However, saying something may cause testicular toxicity is a totally different situation than saying something may improve memory. It's also very different than saying it DOES cause testicular toxicity. That was my initial point in all this. Saying something for sure causes toxicity in humans is a very strong statement that should only be backed by clinical evidence. The state of the science on supplements massively skews towards safety rather than efficacy. You can see this even in the way the FDA enforces the DSHEA as well. They don't send enforcement letters for lack of efficacy, but they do all the time for safety concerns. You also see this in funding for research on supplements. There is just not a whole lot of money in funding studies to show clinical efficacy on dietary supplements in humans, but showing toxicity is controversial enough to get attention. You can also see this with the studies discussing the testosterone in rats as well. They are all non-US studies posted in international journals. I really wish we had more US studies on dietary supplements. I really do! Our system is just not setup to be very helpful in that regard. I think we need to bring back public funding of studies like we had in the past, and remove the money aspect from research, but that's a difficult problem to tackle.

We discussed my issues with those studies in that thread I linked from 8 months ago. I told you my skepticism about the one that showed no issues at reasonable doses, but curiously left the data out. This is my main issue with the arguments about the testicular toxicity issue. They are clearly hiding the data that does not fit the conclusion they wanted. If they make a quick statement that the 100mg/kg and 200mg/kg doses didn't show a reduction in spermatogenesis, but then leave the detailed data out and then only highlight the data from the 300mg/kg dose, how can we trust their conclusions? That's not objective science! Also, they literally say this in the study.

No toxic effect was observed in the animals during the experiment.

So how can we honestly say there is evidence of toxicity to human testicles using that study as evidence? That's the first study. The second had issues that we discussed as well. They measured the LD50 at 200mg/kg. That's a lethal dose for half the rats. So even the lowest dose that they saw decreases in testosterone in was 1/4 the LD50. That shows me this is not clinically relevant. If it takes 1/4 of a lethal dose to show the side effect, it's not relevant to normal doses in humans. Also, what cultivar was this? They got it wild from a wetland in Iran, then did the extraction themselves.

The fresh leaves of Centella asiatica were collected in May 2007 from a local wetland at Bandar-Anzali, Iran.The accuracy of plant selection was proved and authenticated by Dr. Abrahmi, a senior botanist of the Department of Botany, University of Tehran, and a voucher specimen was deposited accordingly at the herbarium of the Department of Plant Sciences at the University of Tehran.

So they just had a botanist look at it? No HP-TLC for ID? No content analysis or heavy metals analysis? How can we be sure of anything to do with this extract? Unlike US studies, where they use USP or Sigma reference materials, they went out into the wild and found the plants themselves, then just had a botanist tell them it was the proper species... That's not scientifically sound for a claim as serious as this! Then what extraction did they use?

The fresh leaves of the plant were air-dried at 40°C and ground to powder, which was then subjected to exhaustive extraction using ethanol in a Soxhlet apparatus. The dark green liquid extract was concentrated under vacuum and the resulting dried extract was lyophilized and preserved in a refrigerator at 4°C until use in the experiments.

So we have zero idea how concentrated this extract is. It was exhaustive, but that is all they say. The fact that they noted the LD50 was 200mg/kg in rats tells me this is a waaaaaay different extract than the one used in the first study. That dose was killing half the rats in this study, but was not even the high dose in the first one. These are serious claims being made, which require serious study design. If they can't even be assed to do proper ID and content analysis of the raw material and extract they are using, how can we trust their conclusions?

Also, we have human clinical studies that discuss not only efficacy, but also toxicity. This is why I don't think it is a risk for people, based on a preponderance of the evidence. I also don't sell things that I think are dangerous or too risky. I absolutely love the effects of nefiracetam, but I won't sell it because I think the risk of renal and testicular toxicity is too high. The same goes for sunifiram. Many people like it, but I don't feel it is safe enough. There are many things that I refuse to sell because I don't think they are safe enough. I have shifted my risk profile since the early days of Ceretropic. You are correct in saying that some of the things we sold on Ceretropic had a pretty high risk profile. People criticized me for it then, and I listened. I skew much more towards safety these days, rather than simply novelty. We always ask ourselves if we think something is safe before considering offering it. We don't just ignore the evidence, either. We dive into it and really try to come to a scientific conclusion. If I honestly thought testicular toxicity from gotu kola was a risk in humans, I would not sell it. I honestly wouldn't.

To your other point about effect statements, I have already spoken to my team about it. Right now they have been using animal studies to suggest that things may help in some regard. That was more as an easy to digest way to help non-technical customers understand why someone might use a product, while not falling afoul of FDA guidelines. They were trying to give simple non-technical bullet points to help customers. However, I suggested that perhaps we reword claims that are arising from animal studies instead of humans ones. Maybe saying "has shown to improve memory in animal studies" would be a better way to word it than "may improve memory." It's not as digestible for the general public, but would be more scientifically accurate. It's never our intention to mislead. We are trying to help educate people. If there are things on our site and blogs that you feel are not scientifically accurate, please tell me. The last thing I want is for people to think we are using bad science to try and sell things to people that don't understand the difference. If it comes across that way, I want to give my team better direction to address that.