ACE-031

What ACE-031 does

ACE-031 traps myostatin and related growth signals. A small trial in women found more lean tissue after one injection. A Duchenne trial stopped after nosebleeds and visible small blood vessels appeared. It has never been approved. In a 2025 laboratory study, none of 14 products sold as ACE-031 contained the trial molecule.

• In a small study of women past menopause, one shot raised lean mass 3.3% and thigh muscle 5.1% by day 29. (Studied in a trial)
• People report using it for bodybuilding, but products sold under this name may hold a different protein. (Reported by users)

Uses in the sources

• Studied for Duchenne muscular dystrophy. The program stopped for safety, and walking benefit was not statistically established. (Studied in a trial) (source)
• A single dose increased lean mass and thigh muscle volume in healthy postmenopausal women. This did not establish functional benefit. (Studied in a trial) (source)
• Self-use is reported for bodybuilding, but market products may contain different proteins and have no reliable dose equivalence. (Reported by users) (source)

ACE-031 dosage

Typical reported dose: 100 mcg in each shoulder, one time

• Single-dose lower boundary: 0.02 mg/kg once once, under the skin. Studied in a trial. Studied in: Healthy postmenopausal women aged 45–75. (source)
• Single-dose 1 mg/kg cohort: 1 mg/kg once once, under the skin. Studied in a trial. Studied in: Healthy postmenopausal women aged 45–75. (source)
• Single-dose 3 mg/kg cohort: 3 mg/kg once once, under the skin. Studied in a trial. Studied in: Healthy postmenopausal women aged 45–75. (source)
• Duchenne 0.5 mg/kg: 0.5 mg/kg every four weeks every four weeks, under the skin. Studied in a trial. Studied in: Boys with Duchenne muscular dystrophy on stable steroids. (source)
• Duchenne 1 mg/kg: 1 mg/kg every two weeks every two weeks, under the skin. Studied in a trial. Studied in: Boys with Duchenne muscular dystrophy on stable steroids. (source)
• Reported shoulder test injections: 100 mcg in each shoulder; 200 mcg total one reported test session, into muscle. Reported by users, rare report. Studied in: Adults discussing self-use for muscle growth. (source)

These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.

Work out syringe units with the dosing calculator

How to store ACE-031

Comes as: Investigational subcutaneous protein preparation, Market injection vials labeled ACE-031.

Mixed with: No verified human-use diluent or mixing volume for market products was located..

• A self-report describes a 1 mg injection; it does not prove vial contents or establish a common vial specification.
• Trial doses were mg/kg of a controlled Fc-fusion product. Market vials cannot be assumed equivalent.
• No trial preparation method was found that supports a home mixing recipe.

Before mixing: No approved storage directions or validated shelf life for market vials were found.

After mixing: No validated post-mixing stability or beyond-use period for market products was found.

ACE-031 side effects and risks

Reported side effects

• Nosebleeds: Duchenne: 1/9 at 0.5 mg/kg; 5/9 at 1 mg/kg; 0/6 placebo., moderate. Stop further exposure and contact a clinician; persistent heavy bleeding needs urgent care. (source)
• Visible small blood vessels on skin: Duchenne: 0/9 at 0.5 mg/kg; 5/9 at 1 mg/kg; 0/6 placebo., moderate. A program-stopping vascular signal; seek review if new spots or bleeding occur. (source)
• Injection-site redness: Duchenne: 3/9 at 0.5 mg/kg; 6/9 at 1 mg/kg; 3/6 placebo., mild. Worsening warmth, fever or spreading redness needs assessment. (source)
• Headache: Duchenne: 1/9 at 0.5 mg/kg; 3/9 at 1 mg/kg; 1/6 placebo., mild. Severe headache with weakness, fainting or vision change needs urgent care. (source)
• Pain, warmth and flu-like symptoms after market products: Isolated self reports; rates and actual product identity unknown., moderate. Stop further use and seek care for persistent fever, severe pain or systemic illness. (source)

Stop and get help if

• Nosebleed lasting over 10–15 minutes, heavy bleeding, dizziness or trouble breathing: Stop further exposure and get urgent care; call emergency services for heavy bleeding or fainting.
• Breathing trouble or swelling of the face or tongue after injection: Call emergency services now.
• Fever with worsening painful injection-site swelling: Stop injections and seek urgent assessment.

Who should avoid it

• pregnant: No pregnancy safety data or validated fetal exposure limits; reproductive-age pregnancy was not studied.
• breastfeeding: No breastfeeding or infant-exposure safety data were found.
• tryingToConceive: Activin pathways affect reproduction; human fertility safety and washout remain unknown.
• under18: The pediatric program stopped for vascular safety concerns; community protocols are restricted to adults.
• bleedingDisorder: Nosebleeds and visible small blood vessels stopped the Duchenne study.
• other: A history of hereditary bleeding-vessel disease raises concern with the observed vascular adverse effects.
• other: Severe allergic-reaction history was excluded from the first human trial.
• activeCancer: Healthy-volunteer studies excluded malignancy; safety during active cancer is unknown.
• cancerHistory: Prior malignancy was generally excluded from healthy-volunteer studies.
• surgeryPlanned: Bleeding risk and long exposure matter; the extension excluded planned surgery. No validated washout exists.
• heartCondition: Significant heart disease outside the Duchenne diagnosis was excluded; safety is uncertain.
• kidneyDisease: Significant kidney disease was excluded; no validated dose adjustment exists.
• liverDisease: Significant liver disease was excluded; no validated dose adjustment exists.
• testedAthlete: ACE-031 is prohibited in and out of competition under WADA S4.3.

Interactions

• Anticoagulants: Bleeding risks may add up. This is a precaution from the trial signal, not a measured interaction.
• Antiplatelets and NSAIDs: These drugs can increase bleeding. Combined risk with ACE-031 has not been measured.
• Other activin or myostatin blockers: Overlapping signaling blockade has unknown safety. No human trial validates this stack.
• Erythropoiesis-stimulating drugs: These medicines were excluded in the multiple-dose trial; the clinical interaction is unknown.

Product quality risks

• None of 14 tested market products contained ACE-031; 12 held full-length receptor without the Fc fusion.
• One product contained follistatin and one ipamorelin. The 12 receptor products contained many extra proteins.
• A wrong receptor protein cannot inherit the trial molecule’s dose, activity or 10–15-day half-life.
• No sterility or endotoxin guarantee follows from identity or purity testing.

What to expect

Four registrations: two published randomized trials, a 70-person multiple-dose trial and an 11-person extension. The last two lack posted results; extension participants overlap the Duchenne trial.

Key studies

• Single dose in 48 women: At 3 mg/kg, lean mass rose 3.3% and thigh volume 5.1% at day 29. (source)
• Multiple doses in 70 women: Completed multiple-dose study has no posted results or located full publication. (source)
• Duchenne randomized trial: Nosebleeds and visible small blood vessels prompted stopping after two dose regimens. (source)
• Duchenne extension, stopped early: Extension stopped on preliminary safety data; no results were posted. (source)
• What the receptor binds: The receptor binds several growth signals; it is not a muscle-only myostatin blocker. (source)
• Marmoset muscle study: Muscle changes in primates do not override the human vascular safety signal. (source)

ACE-031 FAQ

• Is ACE-031 FDA-approved? No. Applying FDA’s protein definition to ACE-031 receptor–Fc protein establishes biological-product status. No FDA-approved product was found.
• How do people take it? Into muscle, one reported test session. One session; symptoms reportedly lasted about a day and a half.. Source: reported by users, not an established dose.
• What's the difference between ACE-031 and Ipamorelin? ACE-031: an experimental muscle-growth protein whose Duchenne program stopped over bleeding concerns. Ipamorelin: an experimental peptide that triggers growth hormone release. Why people pair them: suggested alongside ACE-031 in a muscle-gain discussion.
• Can I take it with Ipamorelin? Suggested alongside ACE-031 in a muscle-gain discussion. No human trial has tested this combination. Added growth-signal and product-quality risks are unknown. Source: reported by users. Ask a doctor before combining anything.
• Is it banned in sport? Yes. It is banned in and out of competition (WADA 2026). Named decoy activin receptor; prohibited in and out of competition.
• How do I store it once opened? No validated post-mixing stability or beyond-use period for market products was found.