Peptide Pens UK: Storage, Handling & COA Checks for Research Pens

For in-vitro laboratory research use only. Not for human or veterinary use. Corex Vitality™ supplies research compounds to adults (18+) for laboratory research. Nothing on this page is medical advice.

Corex Vitality™ offers research peptides in two formats: lyophilised (freeze-dried) vials and pre-filled research pens. This guide explains how our pens are prepared for dispatch, how to store and handle them in the laboratory, which COA applies to each pen, and the current UK price of every pen.

Browse peptide pens UK Search published COAs

Prepared fresh to order, not pre-filled and stored

All peptide pens are prepared fresh to order, so no pen is made up in advance and stored in solution. You choose the strength from the menu on the pen page.

Each pen is filled after your order is placed, using in-stock lyophilised peptide of the strength you selected, then sealed, labelled and dispatched by Royal Mail Tracked 24.

This matters for handling and stability. Peptides are generally more stable as a dry, lyophilised solid than in solution, where hydrolysis, deamidation, oxidation and aggregation can proceed over time [1][2]. Preparing each pen to order keeps the time the peptide spends in solution before it reaches your laboratory short. It also means every pen can be traced to a lyophilised compound with a published COA, which is a quality-control point you can check yourself.

Which COA applies to a pen

The COA linked to a pen is the published COA for the lyophilised compound the pen is prepared from. Purity figures come from that lyophilised COA; the pen solution itself is not separately tested. Our COAs are published exactly as the laboratory issued them, and testing was commissioned by the manufacturer or supplier. To check a COA with the laboratory, follow our guide to verifying a peptide COA.

Storage & handling of research pens

Refrigerate on arrival: store sealed pens at 2–8 °C in a laboratory refrigerator.
Do not freeze a filled pen.
Protect from light and keep the cap on.
Record the date received. A peptide in solution keeps less well than dry powder [1].
Keep the label and COA report number together with your laboratory records for traceability.
Handle all materials under your institution’s laboratory safety procedures.

For storage of lyophilised vials, see the lyophilised peptide storage guide.

Peptide pen prices (UK) & Multi-Pen Savings

Each pen has one clear price. Multi-Pen Savings are applied automatically in the basket: Buy 2 Pens Save £10 and Buy 3+ Pens Save £25, mix and match. Retatrutide pen prices below update automatically from our store. Other pen prices were checked on 2 November 2026; the peptide pens page always shows the current price and availability.

Pen	Strength	Price	Published lyophilised COA
Retatrutide – Pen	20mg	£124.99	Retatrutide 20mg · LDA22160902 · >99.76%
Retatrutide – Pen (Double Strength)	40mg	£159.99	Retatrutide 40mg · LDA22160922 · >99.76%
BPC-157 + TB-500 Blend – Pen	10mg (5mg + 5mg)	£59.99	Blend 10mg + 10mg · LDA22161052 · >99.78% (strength not matched)
BPC-157 + TB-500 Blend – Pen (Double Strength)	20mg (10mg + 10mg)	£89.99	Blend 10mg + 10mg · LDA22161052 · >99.78%
BPC-157 – Pen	10mg	£59.99	BPC-157 10mg · LDA22161152 · >99.73%
TB-500 – Pen	10mg	£72.99	TB-500 10mg · LDA22161162 · >99.69%
KLOW-80 – Pen	80mg	£104.99	KLOW 80mg · LDA22161252 · >99.72%
GHK-Cu – Pen	50mg	£55.99	GHK-Cu 50mg · LDA22160942 · >99.68%
Tirzepatide – Pen	10mg	£132.99	Tirzepatide 10mg · LDA22160842 · >99.69%
Semaglutide – Pen	10mg	£91.99	Semaglutide 40mg · LDA22160962 · >99.76% (strength not matched)
Cagrilintide – Pen	10mg	£104.99	Cagrilintide 10mg · LDA22160972 · >99.73%
CJC-1295 (DAC-free) + Ipamorelin Blend – Pen	10mg (5mg + 5mg)	£74.99	CJC-1295 no DAC 5mg + Ipamorelin 5mg · LDA22161232 · >99.60%
CJC-1295 (DAC-free) – Pen	5mg	£57.99	CJC-1295 no DAC 5mg · LDA22161192 · >99.68%
Ipamorelin – Pen	10mg	£70.99	Ipamorelin 10mg · LDA22161102 · >99.76%
NAD+ – Pen	500mg	£94.99	NAD+ 1000mg · LDA22161142 · >99.77% (strength not matched)
Selank – Pen	10mg	£57.99	Selank 10mg · LDA22161062 · >99.66%
Semax – Pen	10mg	£57.99	Semax 10mg · LDA22161122 · >99.56%
PT-141 – Pen	10mg	£82.99	PT-141 10mg · LDA22161262 · >99.63%

“Strength not matched” means the published COA is for a different sample size of the same compound.

Delivery: pens are prepared within 2 days, then sent by Royal Mail Tracked 24. Free next-day tracked delivery on in-stock orders over £50. See Shipping Information.

Pens or vials?

Lyophilised vials keep longest and let you choose your own solvent and concentration. Pens arrive already in solution and need refrigeration from the day they arrive. For a side-by-side comparison, read pre-filled peptide pens vs lyophilised vials, or browse the full range on our buy research peptides UK hub.

FAQ

Are the pens pre-filled and stored in advance?

No. Each pen is prepared fresh to order: it is filled after your order is placed, from in-stock lyophilised peptide of the strength you chose, then labelled and dispatched. This keeps the time the peptide spends in solution before dispatch short.

How long does pen preparation take?

Pens are prepared and labelled within 2 days of the order, then sent by Royal Mail Tracked 24.

Which COA applies to a pen?

The COA shown is the published COA for the lyophilised compound the pen is prepared from. The pen solution itself is not separately tested. Where the pen strength differs from the COA sample size, the table on this page says so.

How should research pens be stored on arrival?

Keep pens sealed and refrigerated at 2–8 °C, protected from light, and do not freeze them. Record the date received and follow your institution’s laboratory procedures.

How much do multiple pens cost?

Each pen has one price. Multi-Pen Savings apply automatically in the basket: Buy 2 Pens Save £10 and Buy 3+ Pens Save £25, mix and match.

Do you give advice on using research pens?

No. We do not give guidance on human or animal use. Our products are for in-vitro laboratory research only.

Browse peptide pens UK Check a COA

References

All references were checked against PubMed using NCBI E-utilities on 2 Nov 2026. They describe laboratory and analytical research only and are listed for scientific background. They are not claims about any Corex Vitality™ product.

Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544-75. doi:10.1007/s11095-009-0045-6. PMID 20143256
D’Hondt M, Bracke N, Taevernier L, et al. Related impurities in peptide medicines. J Pharm Biomed Anal. 2014;101:2-30. doi:10.1016/j.jpba.2014.06.012. PMID 25044089
Hutchings RL, Singh SM, Cabello-Villegas J, Mallela KM. Effect of antimicrobial preservatives on partial protein unfolding and aggregation. J Pharm Sci. 2013;102(2):365-76. doi:10.1002/jps.23362. PMID 23169345
Grohganz H, Rischer M, Brandl M. Adsorption of the decapeptide Cetrorelix depends both on the composition of dissolution medium and the type of solid surface. Eur J Pharm Sci. 2004;21(2-3):191-6. doi:10.1016/j.ejps.2003.10.008. PMID 14757490

Research use notice

All products supplied by Corex Vitality™ are research chemicals for in-vitro laboratory research only. Corex Vitality™ is the trading name of The Peptide Corex Limited (Company No. 17461435, ICO ZC282346, 5 Brayford Square, London E1 0SG). Our products are not medicines, food, food supplements or cosmetics. Not for human or veterinary use. Published studies are listed for scientific background only. Corex Vitality™ makes no claim that any product treats, prevents or affects any condition.