Nootropics are typically viewed as exotic compounds–sometimes derived from herbal extracts, but more often not based on anything found in nature.
Increasingly however, drug companies are looking for inspiration to a source very close indeed: the human body itself. A new generation of nootropics is being developed that are derived from the body’s own hormones.
One such drug is Dihexa. Dihexa is derived from angiotensin, a natural peptide hormone which promotes vasoconstriction (temporary narrowing of blood vessels) and an increase in blood pressure. It is currently being evaluated for its potential to prevent or reverse Alzheimer’s Disease, and being watched by nootropics communities as a possible brain-boosting drug.
What Does Dihexa Do?
Early studies on mice suggest that Dihexa has synaptogenic activity–it causes the brain to grow more synapses, or connections between brain cells. This was noted particularly in the hippocampus, a region of the brain responsible for consolidating short-term memories into long-term memory.
Another study found that Dihexa enhances the effects of hepatocyte growth factor, a hormone which is partly responsible for causing cells to grow and proliferate throughout the body. This study again noted that the effects particularly seemed to enhance synaptogenesis.
Dihexa’s neurotrophic effects appear to be seven orders of magnitude more powerful than brain-derived neurotrophic factor, or BDNF. Now, this doesn’t necessarily mean that if you take it, you’ll grow a million times more synapses than you naturally would, but it means you’ll grow more synapses, and on a lower dose of Dihexa relative to how much BDNF your brain produces.
Despite its apparent potential for greatly enhancing cell growth, according to the patent Dihexa has so far shown no signs of toxicity or cancer promotion. It seems to be safe…so far.
Bear in mind however that all studies so far have been short-term and performed on mice, which typically live for about two years. We’re still several years away from having human studies, and many more years away from being able to have any confidence in Dihexa’s long-term safety in humans. As such we are not recommending that our readers use Dihexa, only presenting our research on Dihexa for those who are curious about the compound.
One thing to bear in mind is that it is possible to have too many synapses. In fact this has been linked to autism, and is likely the reason why people with autism are so prone to information overload. As such, Dihexa’s synaptogenic activity would likely be harmful to people with autistic spectrum disorder, any family history of autism, or related issues such as difficulty multitasking. In fact, one line of autism research aims to do just the opposite–to help the brain cut down on the number of synapses.
Conversely, Dihexa may be helpful for people who have too few synapses. In the absence of any specific neural disorder, this would mostly mean older people. That is, Dihexa may be useful to counteract the neurological effects of aging well before they progress to dementia. For younger, healthier people however, it should be used with extreme caution, or it should flat out be avoided, given how underdeveloped the research currently is.
Dihexa has not been studied in humans yet, and the only human users so far have been people using it off-label as a nootropic. The human dosage thus needs to be inferred from the mouse dosage, though again, we are not recommending a dosage here because we don’t recommend taking this compound until the quality of the research improves.
In one study, Alzheimer’s mice given 2 mg/kg/day of Dihexa showed clear improvements in cognition within one week. So would humans take 2 mg/kg/day? It’s not clear.
Mouse drug dosages are about 12.3 times higher than human dosages, on a per unit of bodyweight basis. Thus the human-equivalent dose would be 2/12.3, or .16 mg/kg/day. That equates to about 7 to 20 mg/day for most humans, depending on bodyweight. It is also not clear whether the dosage should actually scale based on body size, or should rather be proportional to brain size.
Supplement companies selling Dihexa as a research chemical often recommend 10 to 20 mg a day, if they recommend a dosage at all. This is roughly in line with the research, however remember that Dihexa’s long-term safety for humans has not been established yet.
As such, 5 to 10 mg a day is probably a better guideline from a safety standpoint, at least for healthy individuals. Another possible guideline is that it should be cycled–taken for several months at a time, followed by a multi-month break. However, we want to make clear again that there have been no human studies, nor long-term studies, on the safety of this chemical and are not making any dosage recommendations. Rather, we are relaying the state of research on Dihexa dosage.
Dihexa also has a very long half-life of over a week, so one would expect that it wouldn’t need to be dosed daily.
Who Sells Dihexa?
Science.bio is a relatively new player on the nootropics market, but they’ve quickly made a name for themselves by providing detailed product information, including certificates of analysis, on their product pages.
Their Dihexa powder is kept in a UV-resistant container to minimize sunlight damage, with a tamper-proof seal.
Nootropics Unlimited is one of the most well-known and trusted nootropics suppliers around. They’ve developed a well-earned reputation for putting out pure, no-frills products that work.
Their packaging is relatively simple: reinforced ziplock bags with tamper-proof seals. These bags are thick and durable, and smaller and lighter than the solid containers used by Science.bio. They are however not UV-protected in the same way, so make sure to store them in a dark place.
Liquid Dihexa offers a better value, in terms of cost per milligram, compared to Dihexa powder. It also potentially makes measuring out very small dosages easier.
Liquid Dihexa is also not as stable as powdered Dihexa, although the bottles are darkened for some degree of UV protection. Even so, you may wish to store this in a dark place, perhaps the refrigerator– bearing in mind that cold temperatures may cause it to settle more, since things dissolve more easily at higher temperatures.
Science liquid Dihexa comes in a darker, thicker bottle for better UV protection. It also has less Dihexa overall, so it won’t last as long– but that also means you don’t have to worry about it degrading.
Editor’s note: we are regularly updating this review. If you see any problems, weird interpretations of the data, or just want to say hi, please reach out to firstname.lastname@example.org.