Side-by-side · Research reference

HGH Fragment 176-191vsThymalin

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-DRAFTED12/40 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)

Thymalin

Immune restorer · Russian peptide bioregulator

5–10 mgPer cycle doseKhavinson 2002

HumanMechanisticKhavinson 2002

HoursHalf-life (est)

IM · Daily for 5–10 days · 1-2×/year

01Mechanism of Action

Parameter

HGH Fragment 176-191

Thymalin

Primary target

Beta-3 adrenergic receptors on adipocytesHeffernan 2001

T-cell precursors + thymus-axis maturation pathwayKhavinson 2002

Pathway

Fragment → β3-AR upregulation → Enhanced lipolytic sensitivityHeffernan 2001

Modulation of T-cell differentiation + thymic hormone restoration in age-involuted thymusKhavinson 2002

Downstream effect

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

Restored T-cell populations, improved immune surveillance, reduced infection rates in elderlyKhavinson 2002

Feedback intact?

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

—

Origin

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

Polypeptide fraction isolated from calf thymus extractKhavinson 2002

Antibody development

Not reported in available studies

—

02Dosage Protocols

Parameter

HGH Fragment 176-191

Thymalin

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)

Once daily during cycle

Evidence basis

Animal studies only

Russian clinical + in vitroKhavinson 2002

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

—

5–10 mg / day IM × 5–10 daysKhavinson 2002

Lower / starter dose

—

2.5 mg / day

Duration

—

5–10 day cycles, 1–2× per year

Reconstitution

—

Saline or bacteriostatic water

Timing

—

Morning preferred

Half-life

—

Hours (estimated)

03Metabolic / Fat Loss Evidence

Parameter

HGH Fragment 176-191

Thymalin

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

Thymalin

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.

—

Injection site reaction

—

Mild erythema at IM site

Allergic reaction

—

Rare hypersensitivity to bovine-derived polypeptide

Autoimmune flare

—

Theoretical risk in active autoimmune disease

Long-term safety

—

Limited Western data

Pregnancy / OB

—

Avoid

Absolute Contraindications

HGH Fragment 176-191

·Competitive athletes (WADA-banned)Cox 2015

Thymalin

·Pregnancy / breastfeeding
·Bovine protein hypersensitivity

Relative Contraindications

HGH Fragment 176-191

·Absence of human safety data — experimental use only

Thymalin

·Active autoimmune disease
·Concurrent immunosuppressant therapy

05Administration Protocol

Parameter

HGH Fragment 176-191

Thymalin

1. Route

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

Add 1–2 mL saline or bacteriostatic water per 10 mg vial.

2. Frequency

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

Intramuscular — deltoid or gluteal. Rotate sites.

3. Duration

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

Morning preferred during cycle.

4. Storage

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

Lyophilised: refrigerate, light-protected. Reconstituted: use immediately.

5. Detection

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

23–25G, 25–38 mm IM needle.

06Stack Synergy

HGH Fragment 176-191

— no documented stacks

Thymalin

+ Thymosin α-1

Moderate

View Thymosin α-1 →

Thymalin is a polypeptide complex; Thymosin α-1 is a single purified peptide. Both target the thymus-axis but at different levels — Thymalin restores broad thymic signaling; Tα-1 provides a specific molecular activator. Anecdotally combined for elderly immune support.

Thymalin: 5–10 mg IM · daily × 7 days
Thymosin α-1: 1.6 mg SQ · 2× weekly during the cycle
Primary benefit: Broad thymic restoration + targeted immune activation

Khavinson 2002 Camerini 2001