Milk Thistle - Sovaldi (Sofosbuvir) Interaction
Herbal: Milk Thistle
Also Known As: Silybum marianum, Artichaut Sauvage, Blessed Milk Thistle, Cardo Lechoso, Cardui Mariae Fructus, Cardui Mariae Herba, Carduus Marianum, Chardon Argenté, Chardon de Marie, Chardon de Notre-Dame, Chardon Marbré, Chardon-Marie, Épine Blanche, Holy Thistle, Khar Maryam
Drug: Sofosbuvir
Brand names:
Sovaldi

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Sofosbuvir is classified as belonging to the following category: P-Glycoprotein Substrates
Theoretically, milk thistle might increase the absorption of P-glycoprotein substrates. However, this effect does not seem to be clinically significant.
In vitro research shows that milk thistle can inhibit P-glycoprotein activity and 1 case report from the World Health Organization (WHO) adverse drug reaction database describes increased abdominal pain in a patient taking milk thistle and the cancer medication vincristine, a P-glycoprotein substrate, though this patient was also taking methotrexate. However, a small pharmacokinetic study in healthy volunteers shows that taking milk thistle (Enzymatic Therapy Inc.) 900 mg, standardized to 80% silymarin, in 3 divided doses daily for 14 days does not affect absorption of digoxin, a P-glycoprotein substrate.
Interaction Rating
Likelihood of Occurrence
UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
References
- Gurley, B. J., Barone, G. W., Williams, D. K., Carrier, J., Breen, P., Yates, C. R., Song, P. F., Hubbard, M. A., Tong, Y., and Cheboyina, S. Effect of milk thistle (Silybum marianum) and black cohosh (Cimicifuga racemosa) supplementation on digoxin phar
- Derosa G, Romano D, D'Angelo A, Maffioli P. Berberis aristata/Silybum marianum fixed combination (Berberol(®)) effects on lipid profile in dyslipidemic patients intolerant to statins at high dosages: a randomized, placebo-controlled, clinical trial. Phyto
- Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178.
Interaction Details
Sofosbuvir is classified as belonging to the following category: Sofosbuvir (Solvaldi)
Theoretically, milk thistle might decrease the levels and clinical effects of sofosbuvir.
Animal research in rats shows that milk thistle reduces the metabolism of sofosbuvir, as well as the hepatic uptake of its active metabolite.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Aboras SI, Korany MA, El-Yazbi AF, Ragab MAA, Abdine HH. In-depth investigation of the Silymarin effect on the pharmacokinetic parameters of sofosbuvir, GS-331007 and ledipasvir in rat plasma using LC-MS. Biomed Chromatogr 2022;36(9):e5427.
Milk Thistle Overview

Sofosbuvir Overview
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Sofosbuvir is used along with ribavirin (Copegus, Rebetol, Ribasphere, others) and sometimes another medication (peginterferon alfa [Pegasys]) to treat certain types of chronic hepatitis C (an ongoing viral infection that damages the liver) in adults. Sofosbuvir is also used along with ribavirin to treat certain types of chronic hepatitis C (an ongoing viral infection that damages the liver) in children 3 years of age and older. Sofosbuvir is in a class of antiviral medications called nucleotide polymerase inhibitors. It works by decreasing the amount of hepatitis C virus (HCV) in the body. Sofosbuvir may not prevent the spread of hepatitis C to other people.
Milk Thistle - More Interactions
Milk Thistle interacts with 927 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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Parts of this content are provided by the Therapeutic Research Center, LLC.
DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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Drug descriptions are provided by MedlinePlus.