Hello there! thank you for asking . I read your query and i want you to know that hypothyroidism management is the game of hormones which you need to play very carefully neither to exceed to avoid excacerbations like Tachycardia Palpitations,Atrial fibrillation,Nervousness,Tiredness,Headache, Increased excitability,Sleeplessness,Tremors, Possible angina etc and also avoiding under treatment with thyroixine to avoid subclinical hypothyroidisms or myxedemas or other hypothyroid complications like myxedema coma etc. be cautious when engaging in an activity that poses a risk of injury (eg, operating presses or heavy equipment and driving). Take iodine in diet 150 ug a day minimum. Avoid contact sports and heavy physical labor. Avoid pregnancies to be on the safer road or if necessary be in top obstetricians hannds with constant watch by endocrinologists. Now Melesma/ Chloasma. That can be because of thyroid dysfunction but many other conditions can do that too. like Oral contraceptives, pregnancy, cosmetics, sun exposure, etc. The pigment of melasma develops gradually, and resolution is also gradual. cryotherapy, medium-depth chemical peels, lasers) can help quick but they have adverse effects. I recommend combination treatment with Triple Combination cream followed by laser treatment (1064-nm Q-switched Nd:YAG) it is effective, with no adverse effects. Regardless of the treatments used, all will fail if sunlight is not strictly avoided. Prudent measures to avoid sun exposure include hats and other forms of shade combined with the application of a broad-spectrum sunscreen at least daily. Sunscreens containing physical blockers, such as titanium dioxide and zinc oxide, are preferred over chemical blockers because of their broader protection. UV-B, UV-A, and visible light are all capable of stimulating melanogenesis. But you should remember it will resolve gradually over months.Provided the stimuli are gone in your case Hypothyroidism or sun exposure. Here is the list of medications you can select from 1-Depigmenting agents Hydroquinone (Claripel cream with sunscreens) Hydroquinone 2-Antibiotic agents Azelaic acid (Azelex) Cream 20% 3-Retinoids Tretinoin topical (Avita, Retin-A) But above all you need a team of endocrinologists, Dermatologists and General physicians to manage more pressing concerns and allied troubles to keep you healthy. Hope i was of some help. Take some good care of your self. Regrads Dr S Khan