Side-by-side · Research reference

HGH Fragment 176-191vsSelank

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AAnimal-StrongHUMAN-REVIEWED28/59 cited

BHuman-MechanisticAUTO-DRAFTED11/40 cited

HGH Fragment 176-191

GH Fragment · Pre-Clinical

50%Weight gain reductionNg 2000

~26 minHalf-life (est.)

No IGF-1 ↑GH axis impact

SQ · IP (animal) · Oral (tested)

Selank

Anxiolytic + Cognitive · Russian Pharma

150–300 mcg/doseIntranasalZaderej 2014

HumanMechanisticZaderej 2014 Medvedev 2007

~30 minOnset

Intranasal · 2–3×/day during stress / cognitive demand

01Mechanism of Action

Parameter

HGH Fragment 176-191

Selank

Primary target

Beta-3 adrenergic receptors on adipocytesHeffernan 2001

Monoamine system (serotonin / GABA modulation) + immunomodulation via tuftsin domainZaderej 2014

Pathway

Fragment → β3-AR upregulation → Enhanced lipolytic sensitivityHeffernan 2001

Tuftsin-derived immune signaling + CNS monoamine modulation → reduced anxiety + improved mood / cognitionMedvedev 2007

Downstream effect

Increased lipolysis and beta-3 AR mRNA expression without IGF-1 axis activation

Anxiolytic + cognitive enhancement; immunomodulation via increased IL-6 + IFN-γMedvedev 2007 Zaderej 2014

Feedback intact?

N/A — does not interact with GH/IGF-1 axis

No GABA-receptor binding; no dependence reportedMedvedev 2007

Origin

Synthetic peptide derived from hGH residues 176-191; AOD9604 includes N-terminal tyrosine (177-191)Cox 2015

Synthetic 7-AA peptide derived from human tuftsin (immune-system tetrapeptide)Zaderej 2014

Antibody development

Not reported in available studies

—

02Dosage Protocols

Parameter

HGH Fragment 176-191

Selank

Animal dose (oral)

500 mcg/kg body weightNg 2000

Obese Zucker rats, 19 days.

—

Animal dose (IP)

Not specified (14-day chronic administration)Heffernan 2001

Obese mice, daily IP injection.

—

Human equivalent dose

Not established — no published human RCTs

—

Frequency

Once daily (animal models)

2–3× per day during stress

Evidence basis

Animal studies only

Human-mechanistic + Russian clinical trialsMedvedev 2007

Duration tested

14–19 daysHeffernan 2001 Ng 2000

—

Detection window

50 pg/mL LOD in urine; stable metabolite extends detectionCox 2015

WADA-banned; anti-doping testing available.

—

Oral bioavailability

Demonstrated efficacy in animal oral administrationNg 2000

Potential for oral therapeutic development.

—

Standard dose

—

150–300 mcg / dose intranasalZaderej 2014

Lower / starter dose

—

75 mcg / dose

Duration

—

10–14 day cycles, repeated as needed

Reconstitution

—

Pre-formulated nasal spray (commercial); research vial: bacteriostatic water

Timing

—

Morning + early afternoon preferred

Half-life

—

Short (minutes plasma); CNS effect lasts ~3 hr

03Metabolic / Fat Loss Evidence

Parameter

HGH Fragment 176-191

Selank

Primary fat target

Adipose tissue (general) — beta-3 AR mediated lipolysisHeffernan 2001

—

Weight gain reduction

50% reduction vs control (15.8 ± 0.6 g vs 35.6 ± 0.8 g)Ng 2000

Obese Zucker rats, 19 days oral administration.

—

Body fat reduction

Significant decrease in body weight and body fat in obese mice (14 days)Heffernan 2001

—

Lipolytic activity

Increased adipose tissue lipolytic activityNg 2000

Direct measurement in treated animals.

—

Beta-3 AR expression

Upregulated β3-AR mRNA in obese mice to lean-comparable levelsHeffernan 2001

—

Insulin sensitivity

No adverse effect — euglycemic clamp confirmedNg 2000

Contrasts with intact hGH diabetogenic effects.

—

IGF-1 impact

No elevation — fragment does not activate GH/IGF-1 axis

—

Beta-3 AR dependency

Effect abolished in β3-AR knockout miceHeffernan 2001

Confirms β3-AR as primary mechanism.

—

Route of administration

Efficacy demonstrated via oral and IP routesNg 2000 Heffernan 2001

—

Human evidence

None published — pre-clinical only

—

04Side Effects & Safety

Parameter

HGH Fragment 176-191

Selank

Insulin sensitivity

No adverse effects observed in euglycemic clamp (animal)Ng 2000

—

GH/IGF-1 axis

No activation — avoids diabetogenic effects of full GHNg 2000

—

Human safety data

Not available — no published human trials

—

WADA status

Banned as performance-enhancing drugCox 2015

—

Metabolic profile

Six metabolites identified; CRSVEGSCG most stableCox 2015

Detection window implications for doping control.

—

Nasal irritation

—

Mild burning or congestion (transient)

Sedation

—

None — distinct from benzodiazepinesMedvedev 2007

Dependence / withdrawal

—

None reported in clinical useZaderej 2014

Cognitive impairment

—

None — opposite effect (enhancement)

Allergic reaction

—

Rare hypersensitivity

Long-term safety

—

Limited Western RCT data

Pregnancy / OB

—

Avoid — insufficient data

Absolute Contraindications

HGH Fragment 176-191

·Competitive athletes (WADA-banned)Cox 2015

Selank

·Pregnancy / breastfeeding
·Hypersensitivity to peptide

Relative Contraindications

HGH Fragment 176-191

·Absence of human safety data — experimental use only

Selank

·Active autoimmune disease (theoretical via immunomodulation)

05Administration Protocol

Parameter

HGH Fragment 176-191

Selank

1. Route

Subcutaneous injection primary route in research context. Oral administration demonstrated efficacy in animal models at 500 mcg/kg.

Pre-formulated nasal spray (commercial) or research vial reconstituted with bacteriostatic water.

2. Frequency

Once daily dosing used in animal studies. Timing not specified; GH-independent mechanism suggests flexibility.

Intranasal — 1–3 sprays per nostril per dose. Tilt head slightly back.

3. Duration

Animal protocols: 14–19 days. Human duration not established — no published trials.

Morning + early afternoon for cognitive demand; PRN for acute anxiety.

4. Storage

Lyophilized peptide storage per standard peptide protocols. Metabolite stability suggests refrigerated reconstituted solution viable.

Refrigerate after reconstitution; ≤30 days. Light-protected.

5. Detection

Detectable in urine via SPE-LC-MS at 50 pg/mL LOD. Extended detection window via stable metabolite CRSVEGSCG.Cox 2015

Avoid co-administration with strong sedatives or other anxiolytics initially.