Throw it out and use a new pen from the fridge
Off-Target Considerations The protein fibroblast activation protein-alpha (FAP, Aertgeerts etal., 2005) is the closest relative of DPP-4 (~50% sequence similarity)
To reduce the chance of burning, avoid injecting into visibly irritated skin and give recently treated areas 24 to 48 hours to settle
Behera J, Ison J, Voor MJ, Tyagi N
The American Heart Associations 2025 scientific statement emphasizes that morning bright light exposure (traditionally 10,000 lux, though lower intensities enriched with blue-green wavelengths may suffice) advances circadian phase, improves mood and energy levels, and is associated with lower body fat, body mass, and appetite
This remains preliminary, but it aligns with broader evidence linking GH-IGF-1 signalling to neurological health in ageing populations