Since you have been taking Minoz 50 (Minocycline) since last July without improvement, it is indeed time to consult your dermatologist to revise your treatment. Oral antibiotics for acne typically show results within 8 to 12 weeks, and long-term use is discouraged to prevent antibiotic resistance. Because your current regimen isn't working, your doctor may suggest alternative therapies. Depending on your evaluation, these could include stronger topical retinoids, hormonal therapies (such as spironolactone or oral contraceptives), or oral isotretinoin for resistant acne. Please do not stop or change your medication without your dermatologist's direct supervision.