ARA-290: Reference Overview and Reconstitution Notes

ARA-290 (also called cibinetide) is a small, lab-made protein chain. Researchers study it for possible effects on tissue repair and inflammation. It has not been approved by the FDA for any use.

ARA-290

What it is

ARA-290, also called cibinetide, is a man-made peptide (a short chain of protein building blocks). It contains just 11 amino acids (amino acids are the small molecules that link together to form proteins). It was built from a piece of the erythropoietin (EPO) molecule. EPO is a natural hormone the body makes to signal the production of more red blood cells. Scientists engineered ARA-290 to hold onto the tissue-protecting and inflammation-reducing signals from that part of EPO, but without the red-blood-cell-boosting effect.

Research context and categorization

Classification and Mechanism

Researchers place ARA-290 in the tissue repair and healing category. It is also studied as a compound that may reduce inflammation and help calm the immune system. The way it is thought to work is by attaching to a specific protein on the surface of cells called the innate repair receptor (IRR). Think of a receptor like a lock on the outside of a cell and the peptide as the key. The IRR is formed by two protein pieces joined together (the EPO receptor and the beta-common receptor, also called CD131). Research suggests this receptor appears in greater numbers on cells that are stressed, injured, or inflamed, rather than sitting on healthy cells at all times.

Investigational Scope

In research settings, ARA-290 has been studied and discussed in relation to small fiber neuropathy (damage to the tiny nerve fibers near the skin) linked to sarcoidosis (a disease that causes clusters of inflamed cells to form in body tissues), neuropathic pain (pain that comes from damaged or misfiring nerves), and general tissue-protecting and anti-inflammatory effects.

Key point: Because ARA-290 is not approved by any health authority, its possible uses are strictly investigational and should not be treated as confirmed benefits.

Early studies reported findings such as changes in corneal nerve fiber density (the number of tiny nerve fibers visible in the clear front surface of the eye). These findings come from a limited amount of clinical work and do not establish that the compound is effective or safe.

Status

• Regulatory status: Research-only and not FDA-approved for any use. It has received Orphan Drug and Fast Track designations for sarcoidosis-related neuropathic pain and reached Phase 2 clinical study. It is not an approved therapy and has no licensed prescriber access.
• Sport status: Not listed by name on the WADA Prohibited List (the global anti-doping list of banned substances). However, as a non-approved compound derived from EPO, it would likely be captured under Section S2 (peptide hormones, growth factors, and related substances) and/or Section S0 (non-approved substances). Competitors should treat it as prohibited unless they have clear guidance otherwise, and should confirm with their governing body.

Reconstitution notes (general)

ARA-290 is usually supplied as a lyophilized (freeze-dried) powder. To use it at the lab bench, you add bacteriostatic water (sterile water with a small amount of benzyl alcohol added to slow bacterial growth) to turn the powder back into a liquid. This process is called reconstitution. The concentration of the solution equals the milligrams of powder in the vial divided by the milliliters of water added.

For example, a 10 mg vial reconstituted with 2 mL of bacteriostatic water gives a solution of 5 mg/mL. A concentration calculator is available at peptide calculator.

Dilution and handling notes (compound-specific)

ARA-290 has a known quirk. When mixed at higher concentrations, it tends to turn gel-like, cloudy, or clumpy instead of forming a clear solution. This happens because how well it dissolves depends on pH (a scale from 0 to 14 that measures how acidic or alkaline a liquid is, with 7 being neutral). Bacteriostatic water is mildly acidic, sitting at roughly pH 5.5 to 6.7. ARA-290 dissolves less easily under acidic conditions. Think of it like trying to dissolve a powder in cold, tart lemonade instead of plain, neutral water.

Handling Guidelines

Researchers have found that using a larger volume of water keeps the peptide more dilute and helps avoid gelling. A practical starting point is roughly 1 to 2 mL of water per 5 mg of powder, which gives a solution of about 2.5 to 5 mg/mL. Avoid pushing for a very concentrated mix. Add the water slowly along the inner wall of the vial rather than squirting it directly onto the powder. Gently swirl the vial while the powder dissolves. Do not shake it.

Some researchers report that ARA-290 dissolves more easily in a mildly alkaline buffer, such as phosphate-buffered saline near pH 7.4, than in acidic water. If the solution stays gel-like, hazy, or shows floating particles, the powder did not dissolve cleanly.

Handling and storage

Keep the reconstituted solution refrigerated at 2 to 8 C and away from light. Before drawing from the vial, wipe the rubber stopper with an alcohol swab. Label the vial with the date it was mixed.

A reconstituted peptide in bacteriostatic water is generally treated as usable within about a 4-week refrigerated window. Discard the solution if it becomes cloudy, changes color, or shows floating particles.

Related reading

• Cagrilintide
• Ecnoglutide
• Mazdutide
• How Reconstitution Works
• How Long Does a Reconstituted Vial Last?

Tools and supplies

• peptide calculator
• Bacteriostatic Water 30 ml
• Gansulin Metal Reusable Pen
• 3 ml Glass Cartridges (10-pack)
• Complete Starter Kit

Reminder: research and educational reference only. Preppin Peppers sells hardware and materials, not peptides. Not medical, dosing, or health advice, not evaluated by the FDA, and not intended for human or animal use.

Frequently asked questions

What is ARA-290 and how does it work in research?

ARA-290 is a synthetic 11-amino-acid peptide derived from EPO that is studied for its ability to bind the innate repair receptor (IRR), signaling tissue-protective and anti-inflammatory pathways in laboratory models.

Is ARA-290 FDA-approved or available as a licensed therapy?

No. ARA-290 is not FDA-approved for any use. It holds Orphan Drug and Fast Track designations and reached Phase 2 trials for sarcoidosis-related neuropathic pain but remains strictly a research-only compound.

How is lyophilized ARA-290 reconstituted at the lab bench?

The freeze-dried powder is dissolved in bacteriostatic water; the resulting concentration equals the peptide mass in milligrams divided by the volume of solvent added. No dosing guidance is implied or given.

What the research community gets wrong about ARA-290

ARA-290 (also called cibinetide) is easy to mislabel at the bench. A few points come up again and again in how people talk about it and handle the vials.

• It is not the same as EPO. Because ARA-290 was built from a piece of erythropoietin, people assume it acts like EPO and drives red blood cell production. The published record describes it as non-erythropoietic, meaning it was designed to leave that effect out. This is a description of the peptide in research, not a claim about anyone using it.
• It does not act on cells everywhere the same way. A common shorthand is that it just switches on the ordinary EPO receptor. Studies describe it binding the innate repair receptor, a two-part receptor that appears in greater numbers on stressed or injured cells rather than sitting on every healthy cell.
• A cloudy or gel-like vial is not automatically a bad batch. ARA-290 dissolves less easily in acidic liquid, and bacteriostatic water is mildly acidic. Gelling or haze often points to concentration and pH at mixing time, not always a defective powder. Using more solvent per milligram keeps it more dilute.
• Cibinetide and ARA-290 are one compound, not two. These are two names for the same 11-amino-acid peptide. Seeing both names on paperwork does not mean you have different material.
• Regulatory designations are not approval. Orphan Drug status, Fast Track status, and reaching Phase 2 are steps in a process. They do not mean the compound is approved or that any studied effect is confirmed.

From our bench: If you have reconstituted ARA-290 in bacteriostatic water, tell us the milligrams of powder, the milliliters of water you added, and whether the solution ended up clear, hazy, or gel-like. Note the vial temperature at mixing and how long you swirled. We are gathering real handling observations across concentrations to see where gelling starts, so please share your actual numbers rather than a target.

Sources

1. Bacteriostatic Water for Injection, USP , FDA/DailyMed label (0.9% benzyl alcohol)
2. Duerkop et al., Biotechnol J 2018 , Impact of Cavitation, High Shear Stress and Air/Liquid Interfaces on Protein Aggregation
3. Sigma-Aldrich (Merck) , Handling and Storage Guidelines for Peptides and Proteins
4. PubChem CID 91810664 , Cibinetide (ARA-290), compound record (NIH/NCBI)
5. Heij L, et al. Safety and efficacy of ARA 290 in sarcoidosis patients with symptoms of small fiber neuropathy: a randomized, double-blind pilot study. Mol Med. 2012 (PMID 23168581)