Yes, vitamin C serum can help lighten dark spots and even out lip pigmentation due to its brightening properties
Rodriguez-Barrueco R, Latorre J, Devis-Jauregui L, Lluch A, Bonifaci N, Llobet FJ, et al
[1] This sensation typically relates to the physiological changes that occur during significant weight loss rather than a direct pharmacological effect of the medication itself
Endocrine and metabolic effects of long-term administration of [Nle27] growth hormone-releasing hormone-(129)-NH2 in age-advanced men and women
X.BonischH.GothertM.MolderingsG.RackeK.RamadoriG.et al
Sources: DVLA Assessing fitness to drive guidance, UK CAA medical certification guidance, ICO guidance on UK GDPR and occupational health data, Centre for Perioperative Care (CPOC) guidance