Levothyroxine is a synthetic version of the thyroid hormone thyroxine (T4). It is prescribed to treat hypothyroidism, an endocrine disorder where the thyroid gland does not produce enough thyroid hormones. Common symptoms of hypothyroidism include fatigue, weight gain, dry skin, hair loss, and feeling cold. While levothyroxine is effective at restoring normal thyroid hormone levels, some people report feeling more tired when first starting the medication. In this comprehensive guide, we’ll explore the link between levothyroxine and fatigue and help you understand why you may feel tired when beginning levothyroxine treatment.
Can levothyroxine make you feel tired?
Yes, levothyroxine can make some people feel more tired and fatigued, especially when first starting the medication. There are a few reasons why this temporary increase in fatigue may occur:
Adjusting to proper thyroid levels
When you have hypothyroidism, your body gets used to functioning on low thyroid hormone levels. Restoring hormones to normal levels with levothyroxine is a big change for your system. This adjustment period can leave some people feeling drained as their body regulates to appropriate thyroid functioning.
Stimulating metabolism
Thyroid hormones like levothyroxine help control the metabolism. As levothyroxine kicks in and gets your metabolism going again, you may feel tired as your body works harder to process nutrients and burn energy.
Improving underlying fatigue
Many symptoms of hypothyroidism, including fatigue, don’t immediately resolve once you start taking levothyroxine. It can take 4-6 weeks or longer for your thyroid levels to reach optimal levels and hypothyroidism symptoms to fully improve. As your body recovers, you may go through an initial fatigue phase before your energy levels increase.
Why does levothyroxine make you tired at first?
The reasons why levothyroxine may initially cause fatigue have to do with the medication working to restore normal thyroid hormone function. Here is a more in-depth look:
1. Biochemical changes
Levothyroxine ingestion triggers a complex cascade of biochemical reactions in the body. Thyroid hormones impact the synthesis, breakdown, and mobilization of carbohydrates, fats, and proteins. They also affect the metabolism of vitamins, electrolytes, and hormones.
These widespread biochemical actions aimed at revving up your metabolism require energy. During the transition period, you may feel drained as your body works to biochemically adjust to normalized thyroid hormone levels.
2. Increased metabolic rate
As biochemical processes related to carbohydrate, fat, and protein metabolism accelerate, your basal metabolic rate increases. This reflects how quickly your body uses energy at rest.
Your cells have to work harder to meet the fuel demands of a faster metabolism. This abrupt increase in metabolic output can leave you feeling zonked as your body adapts.
3. Alterations in blood flow
Thyroid hormones cause vasodilation, meaning they make your blood vessels relax and widen. This leads to changes in blood pressure and blood flow to organs and tissues.
Alterations in circulation and blood distribution can contribute to fatigue as your cardiovascular system calibrates to the effects of thyroid hormone on blood vessels.
4. Improvements in underlying issues
Many underlying symptoms of hypothyroidism like sluggishness, weakness, and exhaustion don’t disappear right away after starting levothyroxine. It takes time for thyroid hormone concentrations to build up and hypothyroidism to resolve.
In essence, you are still recovering from the fatigue hypothyroidism causes. As you start feeling a little better, you may perceive it as tiredness linked to the medication.
How long does levothyroxine tiredness last?
For most people, any tiredness or fatigue related to starting levothyroxine is temporary and resolves within a few weeks to a few months.
Here is a general timeline:
First 1-2 weeks
You may begin feeling more drained and sluggish as your body adjusts to the initial effects of levothyroxine. This acute tiredness normally lasts between a few days to a couple of weeks.
First 1-2 months
It typically takes 4-6 weeks for levothyroxine to reach full effect and bring your thyroid hormone levels into the normal range. Fatigue and tiredness related to the transition period can persist during the first month or two.
2-3 months
After two to three months, your body usually adjusts to the appropriate physiological effects of normalized thyroid hormone levels. Any residual tiredness directly linked to starting levothyroxine should resolve within this timeframe.
However, everyone responds differently to medications. Some people feel better in just a few weeks, while others take longer. Work closely with your doctor and be patient during the adjustment period.
Tips for coping with levothyroxine fatigue
Here are some suggestions for dealing with tiredness while your body adapts to levothyroxine treatment:
Allow time for adjustment
Understand that you may not feel completely better right away. Allow your body adequate time to regulate to the medication. Don’t push yourself too hard physically.
Prioritize sleep
Be sure to get enough high-quality sleep, between 7-9 hours per night. Good sleep helps manage fatigue.
Exercise moderately
Light physical activity can help combat tiredness, just don’t overexert yourself. Try walking, swimming, yoga, or stretching.
Reduce stress
Find healthy ways to lower stress, such as meditation, deep breathing, gentle music, or nature walks. High stress exacerbates exhaustion.
Eat energizing foods
Focus your diet on nutritious whole foods like fruits, vegetables, nuts, seeds, legumes, whole grains, and lean proteins to nourish your body.
Avoid alcohol and caffeine
Caffeine and alcohol can disrupt sleep. Minimize consumption, particularly later in the day.
Listen to your body
Take naps or rest when needed. Don’t push yourself too hard. Allow your body time to recuperate.
Be patient
Know that the fatigue is temporary and it takes time for your body to adjust to thyroid hormone changes.
When to see your doctor
Make sure to follow up with your healthcare provider if the fatigue persists longer than 2-3 months or gets progressively worse. They can check that your dose is optimized. Report any bothersome or intolerable side effects.
Also seek medical advice if you develop chest pain, irregular heartbeats, nervousness, tremors, trouble sleeping, appetite changes, fever, chills, body aches, or other symptoms that concern you when taking levothyroxine.
The bottom line
In summary, it is common to feel wiped out and fatigued when first starting levothyroxine treatment for hypothyroidism. The tiredness is generally temporary and related to your body acclimating to normalized thyroid hormone levels. However, speak to your doctor if fatigue lasts longer than 2-3 months or causes major distress. Be patient with yourself and use healthy strategies to get through the adjustment period. Within a few weeks to months, your energy should rebound as the medication takes full effect.