Can you take Wegovy with hypothryoidism?

Jump to: What is hypothyroidism? | What is Wegovy? | Why take Wegovy if you have hypothyroidism? | Thyroid monitoring and management | Important safety considerations | Frequently asked questions | Take home message

You can take Wegovy (semaglutide) if you have an underactive thyroid (hypothyroidism) and your BMI is over 27.

There are no known significant interactions between Wegovy and thyroid medications like levothyroxine, though your thyroid levels should be well-controlled before starting treatment.

Hypothyroidism affects approximately 2-5% of the UK population and can make weight loss more challenging due to its effects on metabolism (how much energy we burn each day).

While there are limited studies specifically examining Wegovy in people with hypothyroidism, the medication wasn’t contraindicated for patients with controlled hypothyroidism in the STEP clinical trials.

Research shows that GLP-1 medications like Wegovy can slightly lower thyroid-stimulating hormone (TSH) levels.

This effect appears to be mild and doesn’t usually require changes to your thyroid medication when starting Wegovy.

However, significant weight loss from Wegovy may eventually require adjustments to your thyroid medication, as thyroid hormone doses are typically based on your weight. This is why regular monitoring of thyroid function throughout your weight loss journey is essential.

What is hypothyroidism?

Hypothyroidism occurs when your thyroid gland doesn’t produce enough thyroid hormones (T3 and T4). These hormones are crucial in regulating your metabolism, energy levels, and weight.

The most common cause of hypothyroidism in the UK is Hashimoto’s disease, an autoimmune disorder where the immune system attacks the thyroid gland. Symptoms often develop gradually and include:

• Feeling tired and weak
• Feeling colder than normal
• Weight gain despite not eating more
• Dry skin and thinning hair
• Low mood and foggy thinking
• Constipation
• Muscle aches and joint pain

Research shows that people with hypothyroidism typically burn 100-400 fewer calories per day compared to those with normal thyroid function. This makes weight loss more difficult, even with diet and exercise.

The condition is usually treated with levothyroxine, which replaces the missing thyroid hormone.

When properly treated, most symptoms improve, including the ability to manage weight more effectively.

Key points:

• Hypothyroidism makes your body burn fewer calories each day, making weight loss harder
• The condition affects 2-5% of people in the UK
• Treatment with levothyroxine helps manage symptoms, but weight loss can still be challenging
• Well-controlled thyroid levels are important before starting any weight loss medication

What is Wegovy?

Wegovy is a once-weekly injection containing the drug semaglutide, approved for weight loss in adults with a BMI over 30, or 27+ with weight-related health issues like high blood pressure or type 2 diabetes.

The medication works in two main ways:

1. Reduces hunger: Wegovy mimics a hormone called GLP-1, which tells your brain you’re less hungry. Many people report much less interest in food, especially ultra-processed and takeaway foods.
2. Slows digestion: Food stays in your stomach longer, making you feel full for an extended time after meals.

Clinical trials show that Wegovy helps people lose about 15-17% of their body weight after 68 weeks, which is much more than the typical 3-5% achieved with diet and exercise alone.

Unlike Mounjaro (tirzepatide), which works on two different hormone receptors, Wegovy works on just one (GLP-1). Both medications help with significant weight loss, though they work slightly differently.

Key points:

• Wegovy is a weekly injection approved for people with a BMI over 30, or 27+ with weight-related conditions
• It works by reducing hunger and slowing digestion
• Clinical trials show 15-17% weight loss after 68 weeks
• It’s different from Mounjaro, which works on two hormone receptors instead of one

Why take Wegovy if you have hypothyroidism?

Weight management can be particularly challenging for people with hypothyroidism. Wegovy may offer several benefits:

1. Helps overcome the difficulty of losing weight: By reducing hunger and food intake, Wegovy can help create a calorie deficit despite your body burning fewer calories with hypothyroidism.
2. May improve thyroid function: Some research suggests that weight loss can improve how well your thyroid works and potentially reduce the amount of thyroid medication you need over time.
3. Addresses related health issues: Many people with hypothyroidism also have conditions that improve with weight loss, such as high blood sugar levels and joint pain.
4. Breaks through weight loss plateaus: If you’ve struggled to lose weight despite well-controlled thyroid levels, Wegovy may provide the extra help you need.

While the benefits are promising, it’s worth noting that Wegovy hasn’t been specifically studied in large groups of people with hypothyroidism.

Some individuals with thyroid problems may still find weight loss more challenging compared to those without thyroid disorders, even with medication support.

Key points:

• Wegovy can help overcome the weight loss challenges caused by hypothyroidism
• Weight loss may improve thyroid function and related health issues
• It can help break through weight loss plateaus when diet and exercise aren’t enough
• Individual results may vary, as hypothyroidism affects everyone differently

Thyroid monitoring and management

If you have hypothyroidism and start taking Wegovy, proper monitoring is essential for several reasons:

How Wegovy affects thyroid hormones

GLP-1 medications like Wegovy can slightly lower TSH levels through effects on your brain’s hormone control centre. This effect is usually mild and not a concern for most people with stable, well-controlled hypothyroidism.

Weight loss and thyroid medication needs

Since thyroid medication doses are based on weight, losing significant weight with Wegovy may eventually mean you need less levothyroxine.

Recommended monitoring schedule

Most thyroid specialists recommend:

• Testing thyroid function before starting Wegovy
• Follow-up testing after 3 months of treatment
• Additional testing after losing 10% or more of your body weight
• Regular monitoring as recommended by your doctor

Signs your thyroid medication may need adjustment

If you experience any of these symptoms while taking Wegovy, talk to your doctor, as they might mean your thyroid medication needs adjusting:

• Fast heart rate or feeling your heart racing
• Feeling anxious, irritable, or nervous
• Excessive sweating or feeling too hot
• Trouble sleeping
• Shaky hands or fingers

Key points:

• Wegovy may slightly lower TSH levels, but this effect is usually mild
• As you lose weight, you may need less thyroid medication
• Regular thyroid function testing is important, especially after significant weight loss
• Watch for signs that your thyroid medication might need adjusting

Important safety considerations

When taking Wegovy with hypothyroidism, be aware of these important distinctions and considerations:

Thyroid cancer risk vs. hypothyroidism

Wegovy carries a warning about the risk of a specific type of thyroid cancer based on animal studies. It’s important to understand:

• This warning is not related to hypothyroidism itself
• Having hypothyroidism does not prevent you from taking Wegovy
• A history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2 (MEN2) does prevent you from taking Wegovy

Telling side effects apart

Some side effects of Wegovy, such as nausea, tiredness, and constipation, can be similar to symptoms of poorly controlled hypothyroidism. This makes monitoring both conditions important to determine what’s causing any symptoms you experience.

Medication timing tips

While there are no known major interactions between levothyroxine and Wegovy, it’s generally best to:

• Take levothyroxine in the morning on an empty stomach
• Take Wegovy on the same day each week
• Allow at least 4 hours between medications when possible

Key points:

• Hypothyroidism doesn’t increase your risk of the rare thyroid cancer mentioned in Wegovy’s warning
• Some Wegovy side effects can be similar to hypothyroidism symptoms
• Take levothyroxine and Wegovy at different times of the day when possible
• Maintain a consistent schedule with both medications

Frequently asked questions

Will Wegovy make my hypothyroidism worse?

No evidence suggests that Wegovy worsens hypothyroidism. In fact, the weight loss achieved with Wegovy may improve your overall metabolic health, which could potentially benefit thyroid function. Regular monitoring ensures your thyroid levels remain well-controlled.

Do I need to adjust my levothyroxine dose when starting Wegovy?

Most people won’t need immediate adjustments to their levothyroxine dose when starting Wegovy.

However, as you lose significant weight (typically more than 10% of your body weight), you may need less levothyroxine. Your doctor will monitor your thyroid function and make adjustments as needed.

Will hypothyroidism reduce Wegovy’s effectiveness?

Well-controlled hypothyroidism shouldn’t significantly impact how well Wegovy works.

However, poorly managed hypothyroidism might affect your overall metabolism and potentially slow down weight loss. This is why ensuring your thyroid levels are optimised before starting Wegovy is important.

Can Wegovy help with weight gain caused by hypothyroidism?

Yes, Wegovy can help address weight gain associated with hypothyroidism by reducing appetite and food intake.

However, it’s important to ensure your hypothyroidism is properly treated with appropriate thyroid hormone replacement first, as medication alone cannot fully compensate for untreated hypothyroidism.

How often should I have my thyroid levels checked while taking Wegovy?

Most thyroid specialists recommend checking thyroid function before starting Wegovy, after about 3 months of treatment, and then following your regular monitoring schedule.

Additional testing is recommended after significant weight loss (10% or more of body weight), as this may affect your levothyroxine requirements.

Take home message

Wegovy can be safely used by people with well-controlled hypothyroidism who meet the BMI criteria for treatment. While the medication may cause modest changes in TSH levels, these effects don’t typically require immediate thyroid medication adjustments.

Regular monitoring of thyroid function is important, particularly after significant weight loss, as you may need less levothyroxine as you lose weight.

Coordinating care between your weight management provider and the healthcare professional managing your hypothyroidism ensures optimal treatment of both conditions.

At Second Nature, we understand the unique challenges that hypothyroidism presents for weight management.

Our programme combines medication support with expert guidance from registered dietitians and nutritionists to help you develop sustainable habits that complement your weight loss journey.