ISO 27001

The independent platform for sharing experiences with medication

The independent platform for sharing experiences with medication

A professional outlook on Levothyroxine

Arjen Walstra

Arjen Walstra


5written expert review(s)


 thyroid - hypothyroidism Effectiveness: 4


Condition for which this medication is usually prescribed

Underactive thyroid

Short description of this condition

An underactive thyroid, or hypothyroidism, is a deficiency of the thyroid hormone. Approximately 10% of people suffer from it and it is often due to an auto-immune disease.

Effect of this medication

When there is not enough of the thyroid hormone it can lead to all sorts of complaints. Some of the complaints that can arise from an underactive thyroid are feeling tired, feeling cold, weight gain and an inability to concentrate. Thyrax, with the active ingredient levothyroxine, is a hormone which naturally occurs in the body and can be supplemented. Because the hormones in the body interact with one another the dosing of Thyrax is a delicate balance between too much and not enough thyroid hormone. Finding the correct dose can sometimes take months. Any alteration to the dose is usually only noticeable after 14 days. It is important that the dosing is as precise as possible because the thyroid hormone also plays an indirect role in bone development. Once the correct dose has been found, it must be taken for the rest of your life.

Advice on this condition

None particular.

Common side effects

Weight gain, feeling tired, excessive sweating.

Advice with regard to these side effects

The side effects are often apparent with too much thyroid hormone. In discussion with your doctor, the correct dose can eventually be found.

Any other expert information?

Levothyroxine must not be taken to lose weight. Using levothyroxine in this manner disrupts the natural balance of hormones in the body. In addition, it is not effective in normal doses, and in too high a dose can be poisonous.