Body Pharm Somatropin 100 Pen (HGH)

The Body Pharm Somatropin 100 IU Pen is a high-concentration, pre-filled pen-format presentation of 191-amino-acid recombinant human growth hormone marketed in South Africa through resellers such as JCSG.org for in vitro and preclinical research procurement. Somatropin is the pituitary-identical 191-aa recombinant GH sequence used as a reference ligand in GH receptor and IGF-1 induction work because its sequence matches endogenous pituitary hormone, making it the standard comparator in receptor-binding assays. At 100 IU per device, this is the highest single-unit IU concentration in Body Pharm's pen range, sitting above the 40 IU pre-filled variant also catalogued locally.

Key Takeaways

• The 100 IU pen consolidates recombinant somatropin into a single sealed cartridge, reducing contamination risk versus ten separate 10 IU vial reconstitutions
• Somatropin drives JAK2–STAT5 signalling with hepatic IGF-1 induction as the primary downstream readout; secondary MAPK/ERK and PI3K/Akt branches mediate lipolytic and myogenic effects
• Schedule 4 control applies in South Africa; procurement requires institutional documentation and ethics clearance for any in vivo work
• Post-reconstitution stability is 14–28 days at 2–8 °C; cold-chain shipping is mandatory
• ZAR pricing ranges R2,000–R3,500 per 100 IU unit (2024–2025 market data)

What Is Body Pharm Somatropin 100 IU Pen?

Body Pharm Somatropin 100 IU Pen is a pre-filled, multi-dose cartridge device containing 100 IU of recombinant 191-amino-acid human growth hormone, manufactured by Body Pharm and supplied through South African research-chemical resellers for in vitro and preclinical use only, not for human administration. The 191-aa sequence is pituitary-identical somatropin with a molecular weight of approximately 22 kDa, produced via recombinant DNA technology in a microbial expression host (expression system not disclosed by Body Pharm; class norms favour an E. coli expression system).

Pen format versus lyophilised vial

The pen houses a sealed cartridge that researchers dial and dispense in IU increments, removing the reconstitution-and-aspiration steps required by lyophilised vials. For lab workflows running repeated low-volume aliquots into cell culture or rodent dosing schedules, this means fewer manipulations per assay and reduced contamination surface, provided the device is paired with a compatible 29–32G screw-on pen needle.

Quick-reference profile:

• Active: somatropin, 191 amino acids, ~22 kDa
• Payload: 100 IU per pen (≈33.3 mg, at the standard 3 IU/mg conversion)
• Format: pre-filled multi-dose cartridge pen
• Classification: research-grade; Schedule 4 under SA law
• Cold-chain shipping: required, 2–8 °C with insulated packaging

Researchers running parallel GH-axis work often pair somatropin reference dosing with downstream IGF-1 LR3 research compound assays or upstream secretagogue protocols using the Body Pharm CJC-1295 & Ipamorelin 20 Pen.

Molecular Profile: 191-Amino-Acid Recombinant HGH

Recombinant somatropin is a single-chain 191-amino-acid polypeptide with a molecular weight of 22,124 Da (≈22 kDa) and a calculated isoelectric point of approximately 5.27, sequence-identical to the mature endogenous pituitary growth hormone encoded by GH1. Two intramolecular disulphide bonds stabilise the chain: Cys53–Cys165 (the large loop) and Cys182–Cys189 (the small C-terminal loop), per the UniProt P01241 entry. For receptor-binding work, that fold geometry positions Site 1 and Site 2 for sequential GHR dimerisation. Any compound failing reducing/non-reducing SDS-PAGE comparison against a reference standard should be rejected before downstream assay use.

Expression system and glycosylation

Body Pharm does not disclose its expression host for the 100 IU pen, and no CMC documentation is published by the South African resellers carrying the product. Class norms for grey-market 191-aa somatropin favour E. coli periplasmic or cytoplasmic expression, which yields a non-glycosylated product. Mature pituitary somatropin is itself not appreciably N- or O-glycosylated, so a CHO-derived equivalent would not introduce meaningful glycan heterogeneity in standard GHR binding or STAT5 phosphorylation assays. Treat the expression system as inferred, not confirmed.

Storage stability

Lyophilised somatropin from comparator brands retains potency for the full labelled shelf life at 2–8 °C. Once reconstituted, preservative-containing multi-dose cartridges such as Humatrope remain valid for 28 days at 2–8 °C, after which residual solution must be discarded. Apply the same 14–28 day refrigerated working window to the Body Pharm pen as a conservative default. Pair somatropin runs with downstream IGF-1 LR3 research compound readouts or upstream Body Pharm CJC-1295 & Ipamorelin 20 Pen secretagogue arms within that envelope.

Signalling Pathways Relevant to Research

Somatropin engages the JAK2–STAT5 pathway as its canonical route. Secondary recruitment of MAPK/ERK and PI3K/Akt branches accounts for the bulk of its mitogenic, metabolic, and lipolytic phenotypes observed in vitro.

Ligand binding drives sequential GHR dimerisation through Site 1 then Site 2 contacts, repositioning the receptor intracellular domains so that constitutively associated JAK2 molecules trans-phosphorylate and recruit STAT5a/b. Phospho-STAT5 dimers translocate to the nucleus and drive transcription of IGF1, SOCS2, and CISH. Hepatic IGF-1 induction remains the most reproducible downstream readout in primary hepatocyte and HepG2 models because of this direct transcriptional coupling.

For lipolysis work in 3T3-L1 adipocytes or primary adipose explants, the MAPK/ERK arm is the more informative branch. ERK1/2 phosphorylation tracks hormone-sensitive lipase activation more tightly than STAT5 output. PI3K/Akt signalling dominates in myoblast and satellite-cell regeneration assays relevant to lean-mass and recovery models, where Akt-mTORC1 flux gates protein synthesis rates.

Researchers running parallel arms with a downstream analogue often pair somatropin treatment against an IGF-1 LR3 research compound to separate direct GHR-driven effects from IGF-1R-mediated ones. When modelling pulsatile versus tonic GH exposure in endogenous-axis preparations, pair somatropin against an upstream secretagogue arm such as the Body Pharm CJC-1295 & Ipamorelin 20 Pen.

Pen Format vs Vial: Practical Lab Considerations

The pen format's main practical advantage is a sealed, pre-loaded 100 IU cartridge that collapses reconstitution into a single bacteriostatic water injection step, reducing the open-vial handling that drives contamination risk in multi-assay runs. The arithmetic is straightforward: 100 IU drawn into 1 ml of bacteriostatic water yields 100 IU/ml (≈33.3 µg/IU × 100 = ~3.33 mg/ml protein); 2 ml yields 50 IU/ml; 2.5 ml yields 40 IU/ml. A conventional 10 IU lyophilised vial workflow requires ten separate reconstitutions to hit the same total IU budget, with ten septum punctures and ten opportunities for endotoxin or microbial ingress.

The trade-off is volumetric inflexibility. Cartridge geometry fixes the diluent volume window, so labs needing very dilute working stocks (for example, 5 IU/ml for low-dose receptor occupancy curves) still have to draw from the pen and serially dilute in sterile PBS or assay buffer. The pen also depends on screw-on insulin-type needles in the 29–32G range, which should be confirmed against a test batch before bulk procurement.

Parameter	100 IU Pen	10 IU Vial (×10)
Total IU per unit	100	10 (×10 = 100)
Reconstitution steps to reach 100 IU	1	10
Septum/seal breaches per 100 IU	1	10
Post-reconstitution storage	14–28 days at 2–8 °C, sealed cartridge	14–28 days at 2–8 °C, per vial
Cost-per-IU implication (2026 ZA market)	Lower per-IU at R2,000–R3,500 per 100 IU pen	Higher, driven by per-vial overhead

Across Body Pharm's own catalogue, the 40 IU pen and 100 IU pen share the same device chassis, so the per-IU cost falls as cartridge fill rises. This is a relevant variable when scaling somatropin arms alongside CJC-1295 & Ipamorelin pen secretagogue controls or IGF-1 LR3 downstream comparators in the same study budget.

Product Specifications at a Glance

The Body Pharm Somatropin 100 IU Pen is a multi-dose pre-filled cartridge of 191-amino-acid recombinant human growth hormone supplied in pen format for in vitro and preclinical research use only.

Parameter	Specification
Compound	Somatropin (recombinant human GH)
Sequence length	191 amino acids, pituitary-identical
Molecular weight	~22 kDa (22,124 Da)
Total IU per pen	100 IU (single cartridge)
Format	Multi-dose pre-filled pen cartridge
Purity grade	Research-grade (CMC data not publicly disclosed)
Storage (sealed)	2–8 °C, protect from light, avoid freeze-thaw
Reconstitution solvent	Bacteriostatic water for injection (recommended)
Post-reconstitution stability	14–28 days at 2–8 °C, sealed cartridge
Needle compatibility	Standard 29–32G screw-on insulin pen tips (confirm with test batch)
Shipping	Cold-chain shipping, 2–8 °C with gel packs
Research classification	In vitro / preclinical only; Schedule 4

Researchers building full GH-axis protocols typically pair this cartridge with downstream IGF-1 LR3 readouts and upstream secretagogue controls such as the Body Pharm CJC-1295 & Ipamorelin 20 Pen. This product is supplied for laboratory research only; it is not licensed for human or veterinary administration and falls within SAHPRA Schedule 4 control for any in vivo use.

Regulatory Context in South Africa (2024–2026)

Somatropin is a Schedule 4 prescription medicine in South Africa under the Medicines and Related Substances Act 101 of 1965. The SAHPRA scheduling tables published in 2024 continue to group recombinant human growth hormone with other prescription-only injectable hormones. Any in vivo or therapeutic supply route requires a valid prescription from a registered medical practitioner. Over-the-counter and general "research chemical" retail of somatropin for human administration is not lawful.

The distinction relevant to laboratory procurement is between therapeutic supply and acquisition of the compound as a research material for in vitro or preclinical work. Schedule 4 control still applies to the substance itself, so procurement records, custody logs, and end-use documentation should align with your institution's chemical procurement policy and be approved by the relevant ethics or biosafety committee before purchase orders are raised.

Researchers planning animal work involving somatropin or its secretagogue partners (for example, CJC-1295 and Ipamorelin combination protocols or downstream IGF-1 LR3 readouts) should additionally clear AREC/animal ethics review.

This is regulatory awareness, not legal advice. Scheduling notices and SAHPRA guidance can be updated mid-cycle. A formal Gazette reference specific to somatropin re-scheduling in 2024–2026 was not located in public records during preparation of this article in March 2026. Verify current status with SAHPRA or institutional legal counsel before each procurement cycle.

Somatropin in the Context of GH-Axis Research

Somatropin is the terminal effector of the somatotropic axis: a 191-amino-acid recombinant growth hormone that binds the GHR dimer and drives JAK2/STAT5 signalling, with hepatic IGF-1 production as its principal downstream readout. For researchers, this position matters because the rest of the GH-axis toolbox either sits upstream of pituitary release or downstream of receptor activation. Assay design usually requires a clear decision about which node is being interrogated.

Upstream, GHRH analogues and ghrelin mimetics stimulate endogenous pulsatile GH secretion rather than supplying the hormone directly. The Body Pharm CJC-1295 & Ipamorelin 20 pen is the most common combination format used in ZA labs to model synergistic GHRH/GHS pathway activation. Tesamorelin offers a stabilised GHRH analogue with a distinct lipodystrophy-focused research profile.

Downstream, IGF-1 LR3 is the long-acting analogue of the primary mediator of somatropin's anabolic and mitogenic effects. It is typically used when researchers want to bypass the GHR entirely and probe IGF-1R signalling in isolation. AOD-9604, a synthetic fragment corresponding to residues 177–191 of hGH, sits outside the canonical signalling cascade and is studied for putative lipolytic activity independent of GHR engagement.

Procurement in South Africa: What to Expect

Procurement of the Body Pharm Somatropin 100 IU Pen in South Africa runs through specialist peptide resellers such as JCSG.org, with tracked domestic courier dispatch, ZAR checkout, and cold-pack packaging appropriate to the 2–8 °C storage requirement of recombinant 191-aa somatropin. Pricing fluctuates with FX and stock; confirm the live R figure on the product page rather than relying on cached values. Third-party listings ranged R2,000–R3,500 per 100 IU unit across 2024 and 2025.

Cold-chain and handling

Because reconstituted somatropin is labelled for 14–28 days of refrigerated in-use stability, request insulated packaging with gel packs for any shipment exceeding 24 hours in transit. Inspect the cold-pack temperature on arrival before logging the batch into your inventory.

Payment and complementary compounds

Checkout is in ZAR with tracked courier confirmation. Researchers building full GH-axis protocols often pair exogenous somatropin with upstream secretagogues such as the Body Pharm CJC-1295 & Ipamorelin 20 Pen or downstream analogues like IGF-1 LR3. View current ZAR pricing on the product page and add to cart for laboratory procurement.

Frequently Asked Questions

Somatropin and HGH refer to the same 191-amino-acid polypeptide produced via recombinant DNA technology to match endogenous pituitary growth hormone. The questions below address procurement, handling, and molecular details most frequently raised by South African research buyers.