ACTH(4-10)
Also known as: Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val · adrenocorticotropic hormone fragment 4-10
The parent 4-10 fragment of adrenocorticotropic hormone from which Semax derives — the classical ACTH-fragment cognitive-research peptide with foundational historical significance in the vasopressin/ACTH memory-peptide programme.
ACTH(4-10) is the parent 4-10 fragment of adrenocorticotropic hormone from which Semax derives — classical historical reference in the ACTH-fragment cognitive-peptide research programme.
Evidence tier: C — preclinical / mechanistic evidence only
- Category
- Cognitive Enhancement
- Half-life
- Short plasma half-life (minutes)
Section 1
Overview
ACTH(4-10) is the 4-through-10 residue fragment of adrenocorticotropic hormone — the pituitary peptide that stimulates cortisol release from the adrenal cortex. The fragment retains ACTH's cognitive-relevant central effects while lacking the endocrine (cortisol-releasing) activity of the parent hormone; the discovery that this separation was possible was the foundational insight that motivated the modern ACTH-fragment cognitive-peptide research programme.
The compound is the direct parent from which Semax derives. Where Semax adds a proline-glycine-proline C-terminal tail to stabilise the fragment against proteolysis, ACTH(4-10) is the unmodified parent fragment. Its plasma half-life is substantially shorter than Semax, limiting its practical research applications, but the compound retains historical and mechanistic significance.
Direct current research use of ACTH(4-10) is limited given the substantial pharmacokinetic advantages of Semax and other analogues. The peptide is included on this reference to complete the classical ACTH-fragment cognitive-peptide family coverage and to provide the mechanistic-and-historical context for Semax's development.
Section 2
Discovery & History
- Identified in the 1960s-70s as the cognitive-relevant fragment of ACTH through systematic peptide-fragment characterisation of the parent hormone.
- Characterised extensively across the 1970s-80s Dutch and Russian research programmes as the foundational reference compound for the ACTH-fragment cognitive-peptide research trajectory.
- Directly informed the development of Semax (Russia) and Org 2766 (Netherlands) as pharmacokinetically-improved analogues addressing the parent fragment's short plasma half-life.
- Never entered clinical development towards marketing authorisation; the derivative analogues (Semax, Org 2766) captured the practical research and clinical-evaluation applications.
- Retains research-chemical availability and historical significance in the ACTH-fragment cognitive-peptide research programme.
Section 3
Mechanism of Action
- 1ACTH-fragment-family central pharmacology without the endocrine cortisol-releasing activity of parent ACTH — the foundational pharmacological property that motivated the entire ACTH-fragment cognitive-peptide research programme.
- 2Reported BDNF and NGF induction in preclinical models — the neurotrophin-induction mechanism that Semax subsequently characterised more extensively and that provides the shared mechanistic framework across the ACTH-fragment analogue family.
- 3Central effects on memory-relevant neurocircuitry consistent with the broader ACTH-fragment family pharmacology, though the mechanism characterisation is less developed than for Semax owing to the pharmacokinetic limitations that restricted the compound's research use.
- 4Modulation of monoamine turnover (serotonin, dopamine) reported in some preclinical characterisation, providing additional angles for the cognitive effects and mechanistic overlap with the Semax mechanism-of-action framework.
- 5Reported effects on stress-response and attention research endpoints in early behavioural pharmacology work, establishing the compound's research-tool relevance for cognitive-relevance research contexts.
- 6The short plasma half-life limits the practical mechanism characterisation depth relative to Semax and other stabilised analogues.
Section 4
Researched Benefits
Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.
- 1Historical foundational significance as the parent fragment from which Semax, Org 2766, and the broader ACTH-fragment cognitive-peptide family derive.
- 2Retains ACTH's cognitive-relevant central effects without the endocrine consequences of the parent hormone — the foundational pharmacological property.
- 3Reference compound for the ACTH-fragment mechanism-of-action framework across the analogue family.
- 4Available as research chemical for specialised historical-context research applications.
- 5Provides mechanistic-and-historical context for interpreting the modern ACTH-fragment cognitive-peptide research (Semax, N-Acetyl Semax, Org 2766).
- 6Limited current research use owing to pharmacokinetic disadvantages relative to stabilised analogues.
Section 5
Theoretical Dosing & Protocols
| Route | Dosage | Frequency | Duration | Source |
|---|---|---|---|---|
| Parenteral (research) | Microgram-range doses in classical research protocols | Multiple daily doses required owing to short plasma half-life | Short courses in classical research contexts | None cited |
Note: The short plasma half-life makes ACTH(4-10) less practical than Semax for most research applications; specific research-context use is generally limited to mechanistic-comparison studies.
Section 6
Administration Routes
- Parenteral administration (subcutaneous, intramuscular, intravenous) — the standard routes in the classical research literature.
- Intranasal administration used in some research contexts but less effective than for stabilised analogues.
- Oral administration is not viable — the peptide is degraded by gastrointestinal proteases.
Section 7
Safety Profile
Commonly reported
- · Generally well-tolerated in the classical research at studied doses.
- · Injection-site reactions with parenteral administration.
- · Occasional mild transient effects during administration.
- · No dependence or withdrawal phenomena documented.
Rare / theoretical
- · Long-term safety data is very limited given the compound's restricted historical research use.
- · Rare hypersensitivity reactions.
- · Residual endocrine effects from the ACTH-fragment origin — minimal at studied research doses.
- · Theoretical interactions with ACTH-family or vasopressin-family pharmaceuticals.
Contraindications
- · No entry for ACTH(4-10) was found in the electronic medicines compendium (emc) on 17 October 2026.
- · Pregnancy and lactation — no controlled data.
- · Known hypersensitivity to peptide components.
Section 8
UK & EU Regulatory Context
United Kingdom
No entry for ACTH(4-10) was found in the electronic medicines compendium (emc) on 17 October 2026. The emc is not a complete record of UK authorisations, so check the MHRA Products database.
European Union
Not approved by the EMA.
Section 9
Clinical Studies Summary
ACTH(4-10) foundational cognitive-fragment characterisation
The classical 1960s-70s characterisation studies establishing ACTH(4-10) as the cognitive-relevant fragment of the parent ACTH hormone, with separation of the central memory effects from the peripheral endocrine cortisol-releasing activity. Provides the foundational reference for the entire ACTH-fragment cognitive-peptide research programme.
ACTH(4-10) memory-modulation research
Classical animal and human research characterising ACTH(4-10)'s memory-modulation effects across multiple learning and cognitive-endpoint paradigms, establishing the parent-fragment pharmacological framework that the derivative analogues (Semax, Org 2766) subsequently extended and refined.
ACTH(4-10) versus derivative analogues comparative pharmacology
Comparative pharmacology studies characterising ACTH(4-10)'s pharmacokinetic and pharmacodynamic profile relative to the stabilised derivative analogues (Semax, Org 2766), demonstrating the pharmacokinetic disadvantages of the parent fragment and the motivation for the analogue-development programmes that produced the practical research and clinical tools.
Section 10
Frequently Asked Questions
Section 10a
Practical Research Guidance
Cycle guidance
Reconstitution & storage
UK sourcing notes
Section 11
Sourcing for Laboratory Research
Sourcing ACTH(4-10) for laboratory research
Researchers in the United Kingdom and elsewhere typically obtain ACTH(4-10) from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.
Reminder: this page is educational. Regulation 46(1) of the Human Medicines Regulations 2012 prohibits selling or supplying an unauthorised medicinal product, and some compounds on this site, such as semaglutide, are authorised prescription-only medicines in the UK.