While TSH (Thyroid-Stimulating Hormone) levels can vary based on age and personal health status, normal TSH levels are generally considered to be in the range of 0.4 to 5.0 micro-international units/milliliter (µIU/mL). However, during the treatment process for thyroid disorders, the target range is typically set at 0.5 to 3.0 µIU/mL.

Typical TSH reference ranges by age for healthy individuals are as follows:
* Newborns (up to 5 days): 0.7 – 15.2 µIU/mL
* Children (1 to 6 years): 0.7 – 5.97 µIU/mL
* Children (7 to 11 years): 0.6 – 4.84 µIU/mL
* Adolescents (12 to 20 years): 0.51 – 4.3 µIU/mL
* Adults (21 to 99 years): 0.27 – 4.2 µIU/mL

It should be noted that these stated ranges are general reference values and may vary depending on the laboratory where the test was performed.