Retatrutide research pens, batch documented and shipped cold chain from the UK. Two formats: the 20mg pen at £139.99 (£7.00 per mg) and the 40mg kit at £220 (£5.50 per mg, the better value). We do not stock the 10mg format because it carries a per milligram penalty with no offsetting benefit. Retatrutide is a triple receptor agonist acting at GLP-1, GIP and glucagon. It holds no MHRA authorisation, is not a licensed medicine, and is supplied for laboratory research use only, never for human or veterinary consumption. Every unit carries a batch number printed on the device and a certificate of analysis naming the issuing laboratory. Before ordering, divide price by milligrams: anything under roughly £3 per mg sits below the production floor and signals underfill or substitution. Read next: price index, cost per week, dosage chart, pen guide, buyer checklist, what retatrutide is.