7 Interactions found for:
Drug Interactions
Moderate
Levothyroxine
+ Ozempic
The following applies to the ingredients: Levothyroxine and Semaglutide (found in Ozempic)
Levothyroxine may interfere with blood glucose control and reduce the effectiveness of semaglutide and other diabetic medications. Monitor your blood sugar levels closely. You may also need additional thyroid function monitoring to ensure your thyroid medication is working properly. It is also recommended to take levothyroxine at least 30 minutes after oral semaglutide. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Drug and Food Interactions
Moderate
Levothyroxine
+ Food
The following applies to the ingredients: Levothyroxine
The timing of meals relative to your oral levothyroxine dose can affect the absorption of the medication. Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects. In addition, absorption of levothyroxine may be decreased and/or delayed by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, calcium fortified juices and grapefruit or grapefruit juice. These foods should be avoided within several hours of dosing if possible. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
The following applies to the ingredients: Levothyroxine
Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Moderate
Ozempic
+ Food
The following applies to the ingredients: Semaglutide (found in Ozempic)
Food may affect the absorption of semaglutide when taken orally. It is recommended that oral semaglutide be taken 30 minutes before first food, beverage, or other oral medications of the day with no more than 4 ounces of plain water. You may experience more side effects including nausea, vomiting, and diarrhea if you fast longer than 30 minutes after the semaglutide dose. Talk to a healthcare provider if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Drug and Pregnancy Interactions
Major
Ozempic
+ Pregnancy
The following applies to the ingredients: Semaglutide (found in Ozempic)
Professional Content
Noncirrhotic metabolic dysfunction-associated steatohepatitis (MASH): This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.
Type 2 diabetes mellitus: This drug should be used during pregnancy only if the benefit outweighs the risk to the fetus.
-According to some authorities: Use is not recommended.
Weight management: Use is not recommended.
AU TGA pregnancy category: D
US FDA pregnancy category: Not assigned
Risk summary: Limited and insufficient data are available on the use of this drug in pregnant women to inform a drug-related risk; based on animal data, this drug may cause fetal harm.
Comments:
-According to some authorities: Contraception use is recommended during therapy for patients of childbearing potential.
-This drug should be discontinued at least 2 months before a planned pregnancy due to the long half-life.
-Additionally for Wegovy:
---A pregnancy exposure registry is available.
---When a pregnancy is recognized, the patient should be apprised of the potential harm to the fetus and discontinue the drug.
Animal studies have revealed evidence of embryofetal mortality, early pregnancy losses, structural abnormalities, and growth alterations. After subcutaneous dosing in rats, rabbits, and cynomolgus monkeys during organogenesis, pharmacologically mediated maternal toxicity (reduced body weight gain and food consumption) was observed at all dose levels. In rats, reduced growth and fetal abnormalities (visceral and skeletal) were observed at the human exposure. In rabbits, early pregnancy losses and increased rates of minor fetal abnormalities (visceral and skeletal) were seen at clinically relevant exposures. In monkeys, sporadic abnormalities (vertebra, sternebra, ribs) occurred at exposures above the human exposure. Exposures at the no observed adverse effect level in all species were subclinical or only slightly higher than the plasma AUC at the maximum recommended human dose; a direct effect of this drug on the fetus cannot be excluded. Salcaprozate sodium (SNAC), an absorption enhancer in the oral tablet, has been shown to cross the placenta and reach fetal tissues in rats; SNAC was associated with increased gestation length, stillbirths, and decreased pup viability following oral dosing in pregnant rats during gestation and lactation. There are no controlled data in human pregnancy.
To monitor the outcomes of pregnant women exposed to this drug, a pregnancy registry has been established. Pregnant women exposed to Wegovy and health care providers are encouraged to contact the manufacturer at wegovypregnancyregistry.com.
Clinical considerations:
-Noncirrhotic MASH: There may be risks to the mother and fetus related to MASH with advanced liver fibrosis (e.g., increased risks of gestational diabetes, hypertensive complications, preterm birth, postpartum hemorrhage); the effect of this drug on these risks is unknown.
-Type 2 diabetes mellitus: Hypoglycemia and hyperglycemia occur more often during pregnancy in patients with pregestational diabetes; poorly controlled diabetes during pregnancy increases the maternal risk for diabetic ketoacidosis, preeclampsia, spontaneous abortions, preterm delivery, and delivery complications and increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity.
-Weight management: Appropriate weight gain based on pre-pregnancy weight is recommended for all pregnant patients because of the obligatory weight gain that occurs in maternal tissues during pregnancy.
AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.
US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.
References
- "Product Information. Wegovy FlexTouch (semaglutide)." Novo Nordisk Ltd (2026):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Ltd 2 (2025):
- "Product Information. Ozempic (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-37 (2025):
- "Product Information. Ozempic (semaglutide)." Novo Nordisk Ltd (2025):
- "Product Information. Ozempic (0.25 mg or 0.5 mg dose) (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd VV-LAB-098353 v10 (2025):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd (2022):
- "Product Information. Wegovy (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-33 (2026):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-30 (2026):
- "Product Information. Wegovy (0.25 mg dose) (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd AU-Wegovy-PI-mPFS VV (2026):
Minor
Levothyroxine
+ Pregnancy
The following applies to the ingredients: Levothyroxine
Professional Content
Use is considered acceptable.
AU TGA pregnancy category: A
US FDA pregnancy category: Not Assigned
Risk summary: No increased rates of major birth defects or miscarriages have been reported with use during pregnancy; untreated maternal hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, gestational hypertension, pre-eclampsia, stillbirth, and premature delivery, as well as potential adverse effects on fetal neurocognitive development.
Comments:
-Thyroid replacement therapy should not be discontinued during pregnancy; hypothyroidism diagnosed during pregnancy should be promptly treated.
-Monitor TSH levels and adjust doses as needed.
-According to some authorities, combination therapy with antithyroid agents for hyperthyroidism is not recommended during pregnancy due to the risk of fetal hypothyroidism from higher doses of antithyroid agents crossing the placenta.
Animal studies have not been conducted. There is a long history of using this drug in pregnant women and this experience has not shown increased rates of fetal malformations, miscarriages or other adverse maternal or fetal outcomes. Hypothyroidism during pregnancy is associated with a higher rate of complications, including spontaneous abortion, pre-eclampsia, stillbirth and premature delivery. Maternal hypothyroidism may have an adverse effect on fetal neurocognitive development. Pregnant women taking this drug should have their TSH measured during each trimester and dose adjusted as appropriate. Patients will generally return to their pre-pregnancy dose after delivery. There are no controlled data in human pregnancy.
AU TGA pregnancy category A: Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.
US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.
References
- "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
- Cerner Multum, Inc. "Australian Product Information." O 0
- "Product Information. Levothyroxine Sodium (levothyroxine)." Fresenius Kabi USA, LLC (2021):
- "Product Information. Synthroid (levothyroxine)." AbbVie US LLC (2024):
- "Product Information. Tirosint (levothyroxine)." IBSA Pharma Inc. (2022):
- "Product Information. Thyquidity (levothyroxine)." Azurity Pharmaceuticals (2020):
- "Product Information. Levothyroxine Sodium (levothyroxine)." Glenmark Pharmaceuticals Europe Ltd (2025):
- "Product Information. Levothyroxine Sodium (levothyroxine)." SERB (2025):
Drug and Breastfeeding Interactions
Major
Ozempic
+ Breastfeeding
The following applies to the ingredients: Semaglutide (found in Ozempic)
Professional Content
Only injectable forms of this drug should be used during breastfeeding.
-According to some authorities: Use is not recommended.
-According to some authorities: Breastfeeding is not recommended during use of the oral form of this drug.
Excreted into human milk: Unknown
Excreted into animal milk: Yes
Comments:
-Injectable formulations: Developmental and health benefits of breastfeeding should be considered as well as the mother's clinical need for this drug. The effects in the nursing infant are unknown; potential adverse effects in the breastfed child due to this drug or the mother's underlying condition should be considered.
---According to some authorities: A risk to a breastfed child cannot be excluded.
-Oral formulations: The absorption enhancer (salcaprozate sodium [SNAC]) and/or its metabolites are present in human milk; enzyme activity involved in SNAC clearance may be lower in infants compared to adults, leading to higher SNAC plasma levels in neonates and infants.
---There is the potential for serious adverse reactions in breastfed infants due to possible SNAC accumulation.
This drug was not detectable in the milk of mothers receiving the subcutaneous formulation. Data from a lactation study with the oral tablet formulation reported drug levels below the lower limit of quantification in human milk.
In a study involving nursing mothers using subcutaneous doses of this drug, milk samples showed no measurable drug levels. If present at the detection limit, the relative infant dose was estimated to be very low. Additionally, breastfed infants of these mothers showed normal growth and development during the period of exposure through breast milk. This drug has poor oral absorption, with a maximum bioavailability of approximately 1% in adults.
Milk samples were collected (at 0, 12, and 24 hours after dosing) from 8 nursing mothers using this drug subcutaneously (0.25 to 1 mg/week); their infants (4 to 23 months old) were mixed fed, receiving breast milk for 3 to 9 weeks during maternal dosing. None of the milk samples contained any measurable drug (less than 1.7 mcg/L), and the mothers reported normal growth and development for their infants. According to author calculation, if drug milk levels were at the detection limit, the relative infant dose would have averaged 1.12%; this did not account for the poor oral absorption of the drug and maximum bioavailability of 1% in adults.
References
- Bethesda (MD): National Institute of Child Health and Human Development (US) "Semaglutide - Drugs and Lactation Database (LactMed) https://www.ncbi.nlm.nih.gov/books/NBK500980/" (2026):
- "Product Information. Wegovy FlexTouch (semaglutide)." Novo Nordisk Ltd (2026):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Ltd 2 (2025):
- "Product Information. Ozempic (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-37 (2025):
- "Product Information. Ozempic (semaglutide)." Novo Nordisk Ltd (2025):
- "Product Information. Ozempic (0.25 mg or 0.5 mg dose) (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd VV-LAB-098353 v10 (2025):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd (2022):
- "Product Information. Wegovy (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-33 (2026):
- "Product Information. Rybelsus (semaglutide)." Novo Nordisk Pharmaceuticals Inc SUPPL-30 (2026):
- "Product Information. Wegovy (0.25 mg dose) (semaglutide)." Novo Nordisk Pharmaceuticals Pty Ltd AU-Wegovy-PI-mPFS VV (2026):
Minor
Levothyroxine
+ Breastfeeding
The following applies to the ingredients: Levothyroxine
Professional Content
Use is considered acceptable
Excreted into human milk: Yes
Comments:
-Levothyroxine (T4) is a normal component of human milk; limited data on exogenous replacement doses during breastfeeding have not shown an adverse effect in nursing infants.
-Levothyroxine dose requirements may be increased in the postpartum period compared to prepregnancy requirements in patients with Hashimoto's thyroiditis.
-The presence of thyroid hormone in breast milk does not appear to interfere with neonatal thyroid screening.
References
- "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical PROD (2002):
- Jansson L, Ivarsson S, Larsson I, Ekman R "Tri-iodothyronine and thyroxine in human milk." Acta Paediatr Scand 72 (1983): 703-5
- Moller B, Bjorkhem I, Falk O, Lantto O, Lafsson A "Identification of thyroxine in human breast milk by gas chromatography-mass spectrometry." J Clin Endocrinol Metab 56 (1983): 30-4
- Mizuta H, Amino N, Ichihara K, et al. "Thyroid hormones in human milk and their influence on thyroid function of breast-fed babies." Pediatr Res 17 (1983): 468-71
- Hahn HB, Spiekerman AM, Otto R, Hossalla DE "Thyroid function tests in neonates fed human milk." Am J Dis Child 137 (1983): 220-2
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Pharmaceutical Society of Australia "APPGuide online. Australian prescription products guide online. http://www.appco.com.au/appguide/default.asp" (2006):
- Cerner Multum, Inc. "Australian Product Information." O 0
- United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
Therapeutic Duplication Warnings
No warnings were found for your selected drugs.Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
Switch to: Professional Interactions
| Drug Interaction Classification | |
|---|---|
These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication. |
|
| Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
| Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
| Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
| Unknown | No interaction information available. |
Disclaimer: This content should not be considered complete and should not be used in place of a call or visit to a healthcare professional. Use of this content is subject to our terms of use & medical disclaimer.