A client who exhibits fatigue, lack of energy, constipation, and depression is diagnosed with hypothyroidism. The physician prescribes levothyroxine (Synthroid). To increase the likelihood of medication compliance in the early course of treatment, the nurse plans to alert the client that:

A. Full therapeutic effect may take 1 to 3 weeks: Levothyroxine (Synthroid) typically starts to show effects within 1 to 3 weeks, but full therapeutic effects may take several weeks to months for symptoms like fatigue and depression to improve. B. Full therapeutic effect may take up to 4 months: Levothyroxine typically shows initial improvement within 1 to 3 weeks, not 4 months. Full stabilization can take a few months, but this is too long for initial effects. C. Diarrhea as an early side effect diminishes with time: Levothyroxine does not typically cause diarrhea. Constipation is more common in hypothyroidism, and any gastrointestinal issues should be reported to the provider. D. Weight gain or edema formation is greatest in the first month: Levothyroxine helps reverse weight gain and edema caused by hypothyroidism. Weight gain is not a side effect of the medication.