Dihexa is a small peptide-like molecule studied for memory tasks in animals and nerve-cell connections in the lab. No human trials were identified, and key early studies carry publication warnings. It is coming soon to Promise.
Coming soon
You are on the list. We will email you when Dihexa becomes available — and nothing else. Joining is not a medical request, and no prescription has been issued.
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Dihexa is coming soon to Promise. Add your email and we'll let you know when visits open.
A licensed provider reviews every request; not everyone qualifies.
Every treatment gets its own online clinical questionnaire — your history, medications, and goals.
A real person goes through your history and takes the time to get it right before anything is decided.
If a treatment isn't right for your history, you'll hear that plainly. That review is the whole point.
Made for your prescription by a licensed U.S. pharmacy and shipped in temperature-safe packaging.
Your care team checks in after it arrives. Adjust with your provider, or cancel at any time.
Dihexa is easy to find online and hard to trust there. Promise works the way medicine is supposed to work — a clinician decides, a licensed pharmacy fills, and someone stays accountable to you.
Prescribed for you specifically, after a real look at your health history — never pulled off a shelf.
Your prescription is compounded for you by a licensed U.S. pharmacy — not a mystery vial from an unregulated website.
Temperature-safe shipping, follow-up check-ins, and a care team that answers — before and after your medication arrives.
Researchers study whether this molecule changes signals between cells through HGF, a messenger protein, and c-Met, its receiver. Animal findings do not establish human benefit.
The direct evidence comes from cell and animal studies. No human trials were identified, and important early papers carry a journal concern or a retraction.
When visits open, a licensed provider will review your health history and medicines, weigh the missing human safety data, and decide whether prescribing is appropriate.
Dihexa is a small, peptide-like molecule studied for memory tasks and nerve-cell connections. That work is in animals and cells, with no human clinical trials identified. Important early papers also carry publication warnings, which makes their findings harder to rely on.
Dihexa is coming soon to Promise — add me to the list.
Researchers at Washington State University developed the compound from angiotensin IV, a short peptide that occurs naturally in the body. Peptides are chains of amino acids, the building blocks used to make proteins. Here, "derived from" means the researchers changed the starting molecule; it does not mean they extracted a natural medicine.
The phrase "dihexa peptide" appears in searches. More precisely, it is a small, modified molecule inspired by a peptide. PNB-0408 is another name used for it in published research. Its name and chemistry describe its identity, without establishing what it would do for a person.
The proposed explanation involves HGF/c-Met. HGF, short for hepatocyte growth factor, is a protein that sends signals to cells. c-Met is the receptor, or cell receiver, that responds to it. Researchers have examined whether the compound changes this signaling in animal and cell models.
The interest includes synapses, the points where nerve cells communicate. Researchers can study those connections in a dish and memory-related behavior in an animal. Neither measurement tells us that a person will remember more or think more clearly.
The 2014 paper tying the compound's reported effects to this system was retracted by its journal in 2025. That history limits how much confidence the early mechanism paper can carry. A proposed explanation needs reliable experiments behind it, as well as human evidence before it can support a clinical claim.
The 2013 rat and cell study examined animals with drug-induced memory-task problems and older rats. Researchers also studied nerve cells grown in the lab. The journal issued a Notice of Concern about this paper in 2021. That is a formal publication warning, distinct from the later paper's retraction.
A water-maze task asks a rat to find a hidden platform. It tests behavior under experimental conditions, rather than how a person manages work, conversations, or a diagnosed memory condition. Cell experiments ask a different question again: what changes in a controlled dish.
Later animal work points in both directions. A 2024 study of 40 rats, in a toxin model that mimics Huntington's disease, found no protection. A 2025 experiment looked at working memory, or holding information briefly, in rats after repeated mild brain injury. Neither answers whether the compound is helpful or safe in people. The sources reviewed did not identify human trials. Human benefits, side effects, and long-term safety remain unknown.
The FDA's compounding safety summary says it has identified no human exposure data for dihexa acetate by any route. It also says key information is missing about whether the substance could harm people. Missing safety data cannot tell us that a compound is safe.
A licensed provider may still prescribe — that decision is between you and your doctor.
Promise's version will be a compounded medication, which is different from an FDA-approved product: it is not FDA-approved. Compounded medications are not reviewed by the FDA for safety, effectiveness, or quality. Provider oversight does not fill the gap in human safety evidence.
These are separate compounds with different starting points. Semax is built from a fragment of ACTH, a hormone made by the body. Its animal research includes BDNF, a protein involved in signals between nerve cells. The compound on this page comes from angiotensin IV and a different line of research.
Selank is another separate peptide in this group. Sharing the Brain Health & Memory category does not make these compounds interchangeable. This page makes no claim about better memory, intelligence, or concentration. Research on one molecule cannot supply missing evidence for another, or establish which one would suit an individual.
When visits open, the process will begin with the intake questionnaire written for this compound. It will cover your health history, medicines, supplements, and the reason for the request. The provider will consider your answers alongside the limits of the evidence.
A licensed provider will then decide whether prescribing is appropriate.
If a provider decides it is appropriate and writes a prescription, a licensed U.S. pharmacy will compound and dispense the medication for you. Your provider sets any protocol; Promise does not publish dosing. Follow-up check-ins from your care team will keep the provider involved after a prescription.
The waitlist is simply a way to hear when visits open. Signing up does not begin that review or settle the prescribing decision.
Dihexa is a synthetic, peptide-like molecule, meaning a small compound built from modified amino-acid building blocks. It was developed from angiotensin IV, a peptide the body makes. Researchers have studied memory tasks in rats and nerve-cell connections in the lab. Human benefits and safety have not been established, and important early papers carry publication warnings.
Yes. When visits open, Dihexa will be prescribed by a licensed provider after a review of your health history and compounded for you by a licensed U.S. pharmacy. It will not be a product labeled for laboratory use. A prescription depends on the provider deciding it is appropriate for you.
A visit does not guarantee a prescription. Once visits open, a licensed provider will review your answers and decide whether Dihexa is appropriate for you. They may ask for more information or decline. The waitlist only lets you hear when visits open; it does not reserve a prescription.
No. Dihexa is not FDA-approved, and no FDA-approved product contains it. The formulation Promise will offer is a compounded medication, which is not reviewed by the FDA for safety, effectiveness, or quality. Being prescribed after provider review does not establish human benefit or resolve the missing safety evidence.
Not yet. Dihexa is coming soon to Promise — add me to the list on this page and we'll email you when visits open. This is a notification list, so signing up does not start a medical visit. Your health history will be reviewed when visits become available.
They are different molecules with different research starting points. Dihexa comes from angiotensin IV and is studied around HGF/c-Met, a system in which a messenger protein meets its cell receiver. Semax is built from a fragment of ACTH, a hormone, and studied around a different nerve-cell signaling protein called BDNF. Neither compound's research can establish results for the other, and this evidence does not rank them.
The research is in cells and animals. An early rat study carries a journal Notice of Concern, and a later mechanism paper was retracted. Other animal experiments do not fill the human evidence gap. No human trials were identified in the sources reviewed, so benefits, side effects, and long-term safety remain unsettled.
Products sold online without a prescription may be labeled for laboratory use and have no responsible provider or patient-specific pharmacy dispensing. When visits open, a Promise prescription will follow a licensed provider's review and, if appropriate, preparation by a licensed U.S. pharmacy, with care-team follow-up. That oversight does not replace missing human safety data.
Other Brain Health & Memory options a provider may consider.
Brain Health & Memory
Two Russian-developed peptides prescribed together: Semax, an ACTH fragment studied around BDNF expression, and Selank, a tuftsin analog studied around anxiolytic signaling.
Requires an online medical evaluation. Prescribed only when a licensed provider determines it's appropriate.
Type a treatment, a goal, or a question.