Using a higher strength pen and “click counting” enables patients to save money on Wegovy® (semaglutide), i.e. to have additional doses from one pen. Hence this has become relatively common practice.  This is ‘unapproved use’ of the product.  We are not aware of problems being demonstrated from this practice.

The manufacturer recommends against “click counting” with Wegovy® pens. They do not guarantee precise dosing unless the full dose is displayed in the window. Sterility is only guaranteed for 6 weeks after opening¹. 

Wegovy® has a wide therapeutic index such that inaccuracy in dosing from “click counting” is low risk to patients. While stability is not guaranteed there is no reason to suspect there will be significant product instability using a pen for a few weeks beyond the manufacturer recommended time. Storing the pen away from heat and light will help prevent degradation².

Theoretically microbial contamination of the pen contents could occur. Wegovy® contains phenol as a preservative which has been shown to maintain sterility for 6 weeks after first opening². NovoNordisk would not advise us if they had studied longer than this timeframe. Sterility testing done by manufacturers to meet regulatory requirements follows standardised protocols and has been demonstrated for 6 weeks².

Another multi-dose semaglutide product manufactured by NovoNordisk, Ozempic®, contains the same excipients as Wegovy® multidose pens and has data to support in-use stability of 8 weeks when stored at room temperature or in the refrigerator³.

Insulin products have similar risk of microbial contamination. From a study⁴ that looked at the sterility of insulin multi-dose vials beyond the recommended manufacturer expiry of 2 months once opened:
–       Twelve vials in total were studied: six contained insulin glargine U100 (Lantus®, 10 mL, Sanofi) containing the preservative metacresol, and six contained protamine zinc insulin U40 (ProZinc®, 10 mL, Boehringer Ingelheim) containing the preservative phenol.
–       Vials were refrigerated, and aspirated twice daily three times weekly for 6 months. Three of each insulin type were alcohol swabbed prior.
–        Microbial contamination was not identified in any vial throughout the study period of 6 months.

To help mitigate contamination we suggest:
–       Storing the pen in the fridge to slow microbial growth.
–       Washing hands prior to administration and administering with a ‘clean’ technique – be careful to avoid contaminating the pen tip or needle.
–       Using a new needle for each dose, insulin pen needles (30G, 31G, 32G up to a length of 8 mm) may be used if there are insufficient needles in the pack.
–       Removing the needle after use and replacing the cap tightly.

As with other unapproved uses of medicines the patient and health care team can weigh the risks/benefits to make an informed decision that benefits the patient most.  

References:

1. Novo Nordisk. (2025, November 12). Personal communication.
2. Datasheet (Wegovy®; Novo Nordisk). Accessed via wegovyinjection.pdf (on 18/11/35)
3. Ozempic®: highlights of prescribing information. Accessed via https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/209637s025lbl.pdf (on 18/11/25)
4. Berg, A.S., Jacob, M.E., Mamo, L.B., Pluta, D.H. and Lunn, K.F. (2023), Refrigerated multi-dose insulin vials remain sterile through 6 months of use. J Small Anim Pract, 64: 776-780. https://doi.org/10.1111/jsap.13664