Cognitive · Reference
Dihexa Dosage: How Pepti Prescribes It, in Units, mL and mg
This page explains the Dihexa dosage Pepti prescribes, what the units on the syringe mean, a dosage chart that converts units to millilitres and milligrams, how long a vial lasts, why the animal studies cannot give you a dose, what can change your directions, and the side effects to know about. It covers how Pepti's Dihexa is typically prescribed, not dosing protocols from the internet. Nothing here is a reason to change your own dose.
Treatments mentioned
At Pepti, Dihexa is prescribed as 0.25 mL, which is 25 units on a U-100 insulin syringe, injected under the skin once daily Monday through Friday. The vial is 5 mL at 1 mg/mL, so each dose carries 0.25 mg (250 mcg) of Dihexa and the vial holds 20 doses, about four weeks. Your physician sets your directions after reviewing your intake, and your exact dose and units are printed on the vial. Dihexa has never been given to people in a published study, so no human dose has been established by research.
This page explains the Dihexa dosage Pepti prescribes, what the units on the syringe mean, a dosage chart that converts units to millilitres and milligrams, how long a vial lasts, why the animal studies cannot give you a dose, what can change your directions, and the side effects to know about. It covers how Pepti's Dihexa is typically prescribed, not dosing protocols from the internet. Nothing here is a reason to change your own dose.
Dihexa Dosage
The short answer
| Product | Vial | Typical directions | Dihexa per dose | Doses per vial | Price |
|---|---|---|---|---|---|
| Dihexa | 5 mL, 1 mg/mL (5 mg per vial) | Inject 0.25 mL (25 units) subcutaneously once daily Monday through Friday | 0.25 mg (250 mcg) | 20 | $219/mo |
Every price is all-in, covering medication, physician review, refill management and shipping, with no separate membership fee. Pepti is cash-pay and does not bill insurance. These are the typical printed directions; your own directions are the ones on your vial. Dihexa is supplied as a vial and syringe only; it does not come as a pen or a capsule.
Dihexa Dosage
What Dihexa is, briefly
Dihexa is a very small peptide derivative built from a fragment of angiotensin IV, itself a breakdown product of angiotensin II. A group at Washington State University designed it to survive in the body and cross into the brain, after reporting that angiotensin IV and its relatives improved memory-task performance in rats. Its full chemical name is N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide; it is also written PNB-0408, and pharmacies label it dihexa acetate. It is not a steroid or a stimulant. The full reference is what is Dihexa.
Dihexa Dosage
Dihexa dosage in units, mL and mg
Pepti's directions are written in two forms, millilitres and units, because prescriptions are written in millilitres and insulin syringes are marked in units. On a U-100 insulin syringe, 1 unit is 0.01 mL, so 100 units is 1 mL and 25 units is 0.25 mL. A unit is a volume mark on the barrel, not a measure of how strong the medication is. Units only mean something alongside the concentration printed on the label.
The milligram figure comes from that concentration. Pepti's Dihexa is supplied at 1 mg/mL, so:
| What you read | Value | Where it comes from |
|---|---|---|
| Dose volume | 0.25 mL | Printed on the vial |
| On a U-100 insulin syringe | 25 units | 0.25 mL x 100 units per mL |
| Concentration | 1 mg/mL | Printed on the vial |
| Dihexa per dose | 0.25 mg (250 mcg) | 1 mg/mL x 0.25 mL |
| Total in the vial | 5 mg in 5 mL | Printed on the vial |
| Doses per vial | 20 | 5 mL divided by 0.25 mL |
That arithmetic is a way to read a label, not a way to set a dose. A vial labelled 5 mg is not a 5 mg dose: it is twenty 0.25 mg doses. If your label and your syringe seem to disagree, do not dose; message your care team. How long does a peptide vial last explains every number on a vial label.
Dihexa Dosage
Dihexa dosage chart: units to mL to mg
People search for a "Dihexa dosage chart" because doses online are quoted in milligrams, micrograms and units interchangeably, and the numbers only line up if you know the concentration. The chart below is the conversion for a 1 mg/mL vial, drawn with a U-100 insulin syringe. It is math only. It is not a menu of doses, and the only line that applies to you is the one that matches the number printed on your vial.
| Syringe mark (U-100) | Volume | Dihexa from a 1 mg/mL vial |
|---|---|---|
| 5 units | 0.05 mL | 0.05 mg (50 mcg) |
| 10 units | 0.1 mL | 0.1 mg (100 mcg) |
| 15 units | 0.15 mL | 0.15 mg (150 mcg) |
| 20 units | 0.2 mL | 0.2 mg (200 mcg) |
| 25 units (Pepti's typical directions) | 0.25 mL | 0.25 mg (250 mcg) |
| 30 units | 0.3 mL | 0.3 mg (300 mcg) |
| 50 units | 0.5 mL | 0.5 mg (500 mcg) |
| 100 units | 1 mL | 1 mg |
The rule behind every row: units divided by 100 gives millilitres, and at 1 mg/mL millilitres and milligrams are the same number. That only holds at 1 mg/mL. A chart from another source, written for a different concentration, a capsule or a powder, gives different figures for the same units, which is the main reason not to dose from a chart, including this one.
Dihexa Dosage
How long a Dihexa vial lasts
At Pepti's typical directions, one 5 mg vial lasts four weeks:
| Step | Value |
|---|---|
| Dose | 25 units, 0.25 mL, 0.25 mg |
| Doses per week | 5 (once daily, Monday through Friday) |
| Doses per vial | 20 (5 mL divided by 0.25 mL) |
| Dihexa used | 20 x 0.25 mg = 5 mg, the whole vial |
| Time per vial | 20 doses divided by 5 per week = 4 weeks |
Four weeks is why refills run every 28 days, one vial per fill. Vials are multi-dose solutions shipped ready to use, refrigerated with ice packs, with sterile syringes and alcohol prep pads. Nothing is mixed at home. Keep the vial in the fridge, out of light, do not freeze it, and follow the beyond-use date printed on the label, which runs from first puncture. How to store peptides covers storage.
If a vial runs short before the refill, message your care team rather than adjusting anything yourself. If you miss a dose, follow your directions and do not take two doses to make up for one.
Dihexa Dosage
When and how Dihexa is taken
Once daily, Monday through Friday
Pepti's Dihexa directions say once daily, Monday through Friday, with weekends off. That is a prescriber convention, not something derived from a human study. It gives 20 doses per vial and a monthly checkpoint, matching the 28-day refill. The printed directions do not name a time of day. Prescribers report trouble sleeping in some people when it is dosed late in the day, and morning dosing is usual; if your physician wants a particular time, your label will say.
Under the skin
Subcutaneous means into the fat layer, not the muscle. Abdomen and thigh are the usual sites, rotated so the same spot is not used repeatedly. There is no reason to inject near the head: the compound was designed to cross into the brain from the bloodstream, and the animal work used ordinary systemic routes. Technique is in how to inject peptides safely.
Directions say What it means in practice 0.25 mL (25 units) Draw to the 25 mark on a U-100 insulin syringe Subcutaneously Into the fat layer, abdomen or thigh, rotating sites Once daily, Monday through Friday Five doses a week, weekends off 20 doses per vial About four weeks, then the next refill Injected or by mouth?
The 2013 paper in the Journal of Pharmacology and Experimental Therapeutics that introduced Dihexa reported that it was active in rats by mouth as well as by injection, which is unusual for a peptide and was a design goal. Pepti supplies it as a subcutaneous injection because that is the route the prescribing and the pharmacy's preparation are built around, and it removes the uncertainty about how much of an oral dose reaches the bloodstream. A capsule or powder sold as Dihexa is not the same product, and any dose figure attached to it does not translate.
Dihexa Dosage
Why the research cannot give you a dose
Most questions about Dihexa dosing assume someone has tested a human dose. Nobody has.
| What exists | What it tells you about dosing |
|---|---|
| Human trials | None: no randomised trials, no open-label trials, no case series |
| FDA's summary | It has not identified any human exposure data on drug products containing dihexa acetate by any route |
| Rat studies (2013) | Better water-maze performance in scopolamine-impaired and aged rats, by mouth or injection; the paper carries a 2021 expression of concern |
| Mouse study (Brain Sciences, 2021) | Better memory-task performance in APP/PS1 mice, from an independent group |
| Mechanism papers (2012, 2014) | Retracted in April 2025 |
Animal doses are set by body weight and do not map onto a compounded vial. The directions on the vial are a prescribing standard set to deliver one vial in four weeks, not the result of a dose-finding study. That is why your directions come from a physician who has reviewed your intake, not from a study table. What research has looked at is in Dihexa benefits.
Dihexa Dosage
Dihexa compared with the products next to it
People often compare a Dihexa dose with the other cognitive products. Here is what each typical printed direction delivers:
| Dihexa | Semax | Selank | |
|---|---|---|---|
| Vial | 5 mL, 1 mg/mL (5 mg) | 5 mL, 2 mg/mL (10 mg) | 5 mL, 2 mg/mL (10 mg) |
| Typical directions | 0.25 mL, once daily Monday through Friday | 0.25 mL, once daily Monday through Friday | 0.25 mL, once daily Monday through Friday |
| Per dose | 0.25 mg | 0.5 mg | 0.5 mg |
| Price | $219/mo | $229/mo | $229/mo |
The same 25 units on the syringe delivers different milligram amounts because the concentrations differ, which is the clearest illustration of why units only mean something next to the label. The three act on different systems, so the milligram figures are not comparable as strengths. Dihexa vs Semax and Selank vs Dihexa compare them.
Dihexa Dosage
What changes the directions
Your physician sets your directions after reviewing your intake. Things that can lead to different directions, or a different product, include:
| What can change | How it shows up |
|---|---|
| Whether Dihexa is the right tool | Unevaluated memory complaints need a work-up first; a physician cautious about Dihexa's evidence base will often suggest Semax |
| Cancer history | Its proposed mechanism runs through HGF/c-Met, a growth pathway over-active in many cancers; a common reason not to prescribe |
| Sleep | Trouble sleeping when dosed late in the day |
| Your other medications | There is no established interaction list, so the intake asks for everything you take |
| How you respond | Headache or a wired feeling that does not settle goes to your physician, who may revise your directions |
When directions change, the new numbers are printed on the new label. Never carry a number over from a previous fill. Bloodwork is not required for any Pepti treatment. If your physician wants labs for your care, they'll ask through your account.
Dihexa Dosage
Side effects, in summary
There is no human safety database for Dihexa. What prescribers report is mostly minor:
| What is reported | When | What to do |
|---|---|---|
| Injection-site redness or soreness | Any time | Rotate sites |
| Headache | Mostly early in a course | Report it if it persists |
| A restless, over-alert or wired feeling | Mostly the first days | Report it if it does not settle |
| Trouble sleeping | When dosed late in the day | Follow the timing on your label |
| Facial or throat swelling, spreading rash, trouble breathing | Rare | Call 911 first, then tell your care team |
If you think you injected far more than your directions, call Poison Control at 1-800-222-1222 and message your care team. Who should not take Dihexa, or should discuss it first: anyone pregnant or breastfeeding, where it is not used; anyone with a personal or strong family history of cancer; and tested athletes, who should check with their anti-doping body (the 2026 WADA Prohibited List does not name Dihexa). The full list is in Dihexa side effects.
Dihexa acetate was placed in Category 2 of the FDA's 503A bulk drug substances list in 2023 because there was no human exposure data. In April 2026 the FDA moved it out of Category 2, and it has announced a Pharmacy Compounding Advisory Committee meeting before the end of February 2027 to consider it for the 503A bulks list. Compounded Dihexa is not FDA approved.
Dihexa Dosage
Where to get Dihexa prescribed
Dihexa cannot be bought legitimately without a prescription. Sites selling it "for research use only" are not accountable for what is in the vial: identity, purity, sterility and concentration are untested, so even the concentration your units chart depends on is unknown. The prescription route:
- Complete a free online intake covering your history, medications, any cancer history and what you want help with.
- A physician licensed in your state reviews it, usually within 24 hours.
- If it is appropriate, a PCAB-accredited, FDA-registered US 503A compounding pharmacy prepares it to that prescription. Lot test results are published at /quality/lab-results.
- It ships refrigerated with your directions printed on the vial.
- Your physician stays reachable for questions and dose changes.
Step by step: how to get Dihexa prescribed online.
References
What this is based on.
References
- McCoy AT, Benoist CC, Wright JW et al.. Evaluation of metabolically stabilized angiotensin IV analogs as procognitive/antidementia agents · J Pharmacol Exp Ther (2013) · PMID 23055539
- Benoist CC, Kawas LH, Zhu M et al.. The procognitive and synaptogenic effects of angiotensin IV-derived peptides are dependent on activation of the hepatocyte growth factor/c-met system · J Pharmacol Exp Ther (2014) · PMID 25187433
- Sun X, Deng Y, Fu X et al.. AngIV-Analog Dihexa Rescues Cognitive Impairment and Recovers Memory in the APP/PS1 Mouse via the PI3K/AKT Signaling Pathway · Brain Sci (2021) · PMID 34827486
- Ho JK, Nation DA. Cognitive benefits of angiotensin IV and angiotensin-(1-7): A systematic review of experimental studies · Neurosci Biobehav Rev (2018) · PMID 29733881
- Wright JW, Harding JW. The Brain Hepatocyte Growth Factor/c-Met Receptor System: A New Target for the Treatment of Alzheimer's Disease · J Alzheimers Dis (2015) · PMID 25649658
- Wright JW, Kawas LH, Harding JW. The development of small molecule angiotensin IV analogs to treat Alzheimer's and Parkinson's diseases · Prog Neurobiol (2015) · PMID 25455861
- Wells RG, Azzam AF, Hiller AL et al.. Effects of an Angiotensin IV Analog on 3-Nitropropionic Acid-Induced Huntington's Disease-Like Symptoms in Rats · J Huntingtons Dis (2024) · PMID 38489193
Citations are provided for educational purposes. They do not constitute medical advice. Always discuss any peptide protocol with your prescribing physician.
Common questions
Dihexa Dosage, answered.
At Pepti, Dihexa is typically prescribed as 0.25 mL, which is 25 units on a U-100 insulin syringe, injected subcutaneously once daily Monday through Friday. From the 1 mg/mL vial that is 0.25 mg per dose. Your physician sets your directions after reviewing your intake, and your exact dose is printed on the vial.
The amount printed on your vial, on the schedule printed on your vial. If you have questions about your dose, message your care team.
The number printed on your vial. Pepti's typical directions are 25 units, which is 0.25 mL on a U-100 insulin syringe.
From a 1 mg/mL vial, 0.25 mg, or 250 mcg. 10 units is 0.1 mg and 50 units is 0.5 mg. Those figures only hold at 1 mg/mL.
Not from research. There are no human trials of any kind, and the FDA has identified no human exposure data by any route.
The printed directions say once daily on weekdays without naming a time. Prescribers report trouble sleeping when it is dosed late in the day, and morning dosing is usual. Follow your label.
About four weeks: 20 doses of 0.25 mL on weekdays uses the whole 5 mg vial.
At Pepti it is a subcutaneous injection. A 2013 rat study reported activity by mouth as well, but an oral product is not the same thing, and its dose figures do not translate.
No. Take the dose printed on your vial. No study has tested any dose in people, so there is no evidence that more does more.
Some physicians prescribe the two together because they act on different systems; no study has tested the combination. Raise it with your physician rather than adding a product yourself.
No. Pepti vials are multi-dose solutions shipped ready to use, with sterile syringes and alcohol prep pads.
Bloodwork is not required for any Pepti treatment. If your physician wants labs for your care, they'll ask through your account. The free assessment goes to a physician licensed in your state. A consultation does not guarantee a prescription.
Next step
See what a physician recommends for you.
A licensed physician in your state reviews your intake and decides what is appropriate. A consultation does not guarantee a prescription.