MK-677 (also known as Ibutamoren / Acetomoren) is an oral growth hormone secretagogue -  meaning it encourages your body to release more of its own growth hormone (GH) and IGF-1, rather than replacing them from the outside.

It works by activating the ghrelin receptor (GHS-R1a) in the brain and pituitary gland, which is one of the body’s natural control switches for GH release. When stimulated, this pathway can help increase pulsatile, GH secretion, raise IGF-1 levels, a key hormone involved in tissue repair and body composition, and support processes linked to recovery, muscle, bone and metabolic health

MK677 is not an FDA-approved medicine and is not intended to diagnose, treat, cure or prevent any disease. It should always be used under guidance from a qualified healthcare practitioner.

When used as directed and with professional supervision, clients commonly use MK-677 to help support:

Recovery from training & physical stress

By elevating GH/IGF-1 signalling, MK-677 is often used to support muscle and connective-tissue recovery between sessions or during heavy training blocks.

Lean muscle support & performance progress

In the context of adequate protein intake and a structured resistance-training program, MK-677 may help support lean mass, strength progression and training consistency.

Body composition & metabolic health

Some protocols use MK-677 as part of body-recomposition strategies to help protect muscle while addressing fat mass, always alongside diet and movement.

Bone & connective-tissue support (advanced programs)

GH/IGF-1 have roles in bone turnover and connective tissue. Clinicians may include MK-677 within broader healthy-ageing or structural-support programs.

Healthy-ageing & vitality support

Due to its influence on GH and IGF-1, MK-677 is sometimes used in longevity-focused protocols aimed at maintaining tissue quality, function and resilience with age.

*Individual results vary. MK677 is best used as one part of a complete program tailored by your practitioner and is not a replacement for medical treatment.

Active Ingredient

MK-677 (Acetomoren / Ibutamoren) – 25 mg per capsule

Presentation

100 capsules per bottle

Protocol & Standard Dosing

Standard Dose

• 1–2 capsules daily
• 1 capsule = 25 mg

Daily total dose = 25–50 mg, as directed by the prescribing practitioner.

Administration

Swallow capsules whole with water.

Timing

Once daily, commonly:

• In the evening (some users find this suits their routine and recovery focus), or
• In the morning, depending on practitioner preference and individual response.

Can be taken with or without food – follow your clinician’s instructions.

Frequency & Course Length

Daily use, with typical cycle lengths ranging from 8–12 weeks or longer, depending on goals, tolerance and monitoring outcomes.

Any long-term or repeated-course use must be regularly reviewed by your healthcare practitioner (including blood work where appropriate).

Dosing & Administration Instructions

• Start at the lowest effective dose recommended by your clinician (often 1 capsule daily).
• Do not increase beyond 2 capsules (50 mg) per day without explicit practitioner approval.
• Take at the same time each day for consistency.
• Do not share with others.

Side Effects, Reactions & Medical Contraindications

Use is generally not recommended in:

• Known allergy or hypersensitivity to MK-677 or any capsule ingredient
• Pregnancy or breastfeeding (insufficient safety data; not appropriate)
• Individuals under 18 years of age
• Active malignancy or history of cancer unless cleared and closely monitored by a specialist (due to potential effects on growth pathways)
• Poorly controlled diabetes, prediabetes, metabolic syndrome or significant insulin resistance without specialist supervision (due to potential impacts on blood glucose and insulin)
• Significant cardiovascular disease, oedema, uncontrolled hypertension or history of heart failure (fluid retention can be an issue)
• Severe kidney or liver disease without specialist oversight
• Individuals subject to professional or federation anti-doping testing (WADA / similar), as GH secretagogues are generally prohibited in tested sports

Always disclose all existing medical conditions and medications to your prescribing clinician before starting MK-677.

Common Side Effects and Adverse Reactions – Often dose-related, and may be more likely at higher daily doses:

• Increased appetite
• Fluid retention & puffiness
• Mild peripheral oedema (swollen ankles, fingers), feeling “puffy” or heavier, especially early in use.
• Joint pain or stiffness
• Some users experience joint aches or carpal-tunnel–like symptoms due to GH/IGF-1–related fluid changes.
• Fatigue or altered sleep
• Some may feel more tired initially, while others report vivid dreams or changes to sleep pattern.
• Metabolic shifts
• Increases in fasting glucose, insulin or changes in lipid profiles can occur and should be monitored via blood tests in longer courses.

If these symptoms are persistent, uncomfortable or worrying, contact your healthcare provider. Dose reduction, cycling or discontinuation may be necessary.

Reactions Requiring Medical Attention – Stop use and contact a healthcare provider (or emergency services if severe) if experiencing:

Signs of a serious allergic reaction

• Widespread rash, hives
• Swelling of the face, lips or tongue
• Difficulty breathing or swallowing
• Marked or rapidly worsening oedema:
• Significant swelling of ankles/legs, shortness of breath lying flat, or sudden weight gain
• Cardiovascular symptoms:
  • Chest pain
  • Severe shortness of breath
  • Palpitations, or sudden dizziness
• Neurological or severe musculoskeletal symptoms:
  • Severe headaches
  • Visual disturbances
  • Significant numbness/tingling in hands
  • Severe joint or muscle pain
• Any new or worsening symptom that feels serious, unusual or concerning

Safety Note

MK-677 (Ibutamoren) is an investigational growth-hormone secretagogue. Long-term safety data in humans are limited, and use is off-label in most settings. Because of this:

It must only be used under the care of a qualified clinician familiar with GH secretagogues.

Appropriate baseline and follow-up blood tests (e.g. glucose, HbA1c, lipids, IGF-1) and blood pressure/weight checks are strongly recommended.Safety Note: Long‑term data is limited. Use should always be monitored by a qualified clinician, with regular reviews and ongoing medical supervision.  Informed consent is essential.