A 2015 research review linked taking too much B12 to acne, rosacea, vitiligo, and atopic dermatitis
Once we have a clear picture of root causes whether its SIBO, candida, parasites, food sensitivities, or a combination we build a layered protocol: remove the offending agents, support digestion and detoxification, and then deploy targeted peptides to accelerate mucosal repair
GHK-Cu (sister peptide) given by intraperitoneal injection at 0.2/2/20 micrograms/g in mice reduced pulmonary fibrosis via Nrf2/NF-kB/TGF-beta1-Smad2/3 demonstrates systemic-injection dosing of the copper-tripeptide class in animals, relevant to the injectable question but GHK-Cu, lung, mouse
Presented for research literature review only Nazar-Stewart V et al
It added an incredible amount of sediment and turbidity, and it changed the chemistry and biota
As you are technically absorbing lower amounts of B12 over time, it might take a while for symptoms to reduce