Thyroidinum is a not too often used drug. I myself have used it only in a handful of cases chiefly as an intercurrent. In one case of Psoriasis though, I have used it as a first prescription. One must refrain from using it as a specific prescription for Myxedema or hyperthyroidism.
 

THYROIDINUM            Source: animal-sheep PROVER                       MIASM: Psora, sycosis, tubercular
CAUSE	Myxedema, scleroderma, syphilis, tetanus, anemia, valvular heart  disease
MIND	Depression alternates with mania. Hysteria. Weeping, homicidal, dangerous, quarrelsome, suspicious, persecuted, excited, nightmares, laughing, grunting
HEAD	Abnormal hair growth/ hair fall. Grey
EYES	Optic neuritis
FACE	Flushes with distant pains. Burning, desquamation Swelling
MOUTH	Thirsty, ulceration cheek
THROAT	Goitre
HEART/CHEST	Palpitation, angina, cardiac arrest. Cardiac failure  Faintness.Tachycardia,. Breathless, livid, dying.
STOMACH	Indigestion
ABDOMEN	Diarrhea, constipation
URINARY	Increased in diabetes
FEMALE	Early, profuse, prolonged menses
EXTREMITIES	Quivering, tremors
SKIN	Psoriasis. Blue-black skin, great  desquamation, stiffness
FEVER	Flushing, high fever unconsciousness, back pain.
PECULIAR SYMPTOMS	Stooping=palpitation. Depression alternates with mania. Homicidal, persecution, suspicious. > recumbent.