Can Antibiotics Raise Your Cholesterol Level? A Deep Dive

October 13, 2025 •

4 min read

Studies show that pharmacological disruption of the gut flora by antibiotics can exacerbate serum cholesterol [1.2.1]. But can antibiotics raise your cholesterol level directly, and which types are implicated? This complex interaction involves your gut microbiome, liver function, and even other medications.

Quick Summary

The link between antibiotics and cholesterol is complex; some types may increase LDL while others might lower it. The primary mechanism involves disruption of the gut microbiome, which alters cholesterol metabolism and bile acid cycling.

Key Points

Gut Microbiome Disruption: The primary way antibiotics affect cholesterol is by altering the gut microbiome, which is crucial for metabolism and bile acid cycling [1.5.1].
Variable Effects: Not all antibiotics raise cholesterol; some, like metronidazole, can lower it, while others, like macrolides, may increase it [1.2.4, 1.3.1].
Mechanism of Increase: Some antibiotics can increase intestinal cholesterol absorption or boost the liver's cholesterol production by affecting enzymes like HMG-CoA reductase [1.2.1, 1.3.7].
Statin Interaction: Certain antibiotics, particularly macrolides and clindamycin, have been shown to increase LDL cholesterol in patients taking statins [1.2.3].
Clinical Communication: Patients on cholesterol-lowering therapy should always inform their doctor about any new antibiotic prescriptions for proper monitoring and management [1.7.2].
Dietary Influence: The effect of antibiotics on cholesterol can be influenced by diet; one study noted increases occurred in mice on a normal diet but not a Western-style high-cholesterol diet [1.2.1].
Reversible Changes: Elevations in cholesterol caused by short-term antibiotic use can be reversible after the treatment is stopped and the gut microbiota begins to recover [1.2.1].

The Unexpected Link: Antibiotics and Cholesterol Metabolism

The question of whether antibiotics can affect cholesterol levels is a topic of growing scientific interest. While not a universal side effect for all antibiotics, evidence suggests certain types can influence lipid profiles, sometimes increasing harmful cholesterol and at other times, surprisingly, lowering it [1.2.4, 1.3.1]. The primary mechanism behind this connection lies in the profound impact antibiotics have on the gut microbiome [1.5.1]. The gut is home to trillions of microorganisms that play a crucial role in numerous bodily functions, including metabolism. These bacteria help process dietary fats and are integral to the cycling of bile acids, which are synthesized from cholesterol in the liver [1.4.1]. When antibiotics are introduced, they don't just target pathogenic bacteria; they can also disrupt this delicate ecosystem, a condition known as dysbiosis [1.5.5]. This disruption can alter how the body absorbs and processes cholesterol.

How Gut Dysbiosis Influences Cholesterol

Pharmacological disruption of the gut microbiome can lead to several changes that collectively impact cholesterol levels. A 2022 study found that antibiotic treatment in mice led to increased serum cholesterol, particularly LDL (low-density lipoprotein) and VLDL (very-low-density lipoprotein), when the animals were on a normal diet [1.2.1]. The researchers pointed to a few key microbial mechanisms: increased intestinal cholesterol uptake, reduced bile acid cycling, and diminished levels of plant sterols [1.2.1]. Essentially, by altering the gut flora, antibiotics can inadvertently enhance the body's absorption of cholesterol from the intestines. Furthermore, research in rats has shown that certain antibiotics, like amoxicillin and pefloxacin, can increase the activity of HMG-CoA reductase, the same enzyme targeted and inhibited by statin drugs [1.3.7, 1.4.2]. Increased activity of this enzyme leads to higher cholesterol production (cholesterogenesis) in the liver [1.3.7].

Which Antibiotics Are Implicated?

The effect on cholesterol is not uniform across all antibiotic classes. Research has highlighted specific groups that may either raise or lower lipid levels.

Antibiotics That May Increase Cholesterol: Studies have associated macrolides (like azithromycin) and lincosamides (like clindamycin) with increases in LDL cholesterol, particularly in patients who are already taking statins [1.2.3]. One study found that macrolide exposure was related to both hypercholesterolemia (high cholesterol) and hypertriglyceridemia (high triglycerides) [1.3.1]. Amoxicillin and pefloxacin have also been shown to induce cholesterogenesis in animal studies [1.6.1].
Antibiotics That May Decrease Cholesterol: Conversely, some antibiotics have demonstrated a cholesterol-lowering effect. One study found that metronidazole markedly reduced LDL cholesterol by 14% [1.2.4]. Doxycycline and sulfaclozine have been associated with decreases in total cholesterol levels [1.3.1]. An older but significant study also noted that oral neomycin produced a significant fall in serum cholesterol [1.2.2].

This variability underscores the complexity of the antibiotic-microbiome-host interaction. The outcome can depend on the specific antibiotic, the duration of treatment, the individual's baseline gut flora, and their diet [1.2.1].

Comparison of Antibiotic Effects on Lipids


Antibiotic Class / Example	Reported Effect on Cholesterol	Primary Mechanism (if known)
Macrolides (e.g., Azithromycin)	Associated with increased LDL in statin users and hypercholesterolemia [1.2.3, 1.3.1]. Stimulates cholesterol accumulation in some cells [1.6.6].	May interfere with statin absorption via gut microbiota changes; induces phospholipidosis [1.2.3, 1.3.3].
Fluoroquinolones (e.g., Ciprofloxacin)	Associated with increased triglycerides and risk of hypercholesterolemia [1.3.1].	Disruption of gut microbiota [1.3.1].
Metronidazole	Markedly reduced LDL cholesterol (-14%) and oxidized LDL (-23%) in one study [1.2.5].	Alteration of colonic microflora; may be linked to an increase in Bifidobacteria [1.2.5].
Tetracyclines (e.g., Doxycycline)	Associated with decreased total cholesterol levels and reduced risk of hypertriglyceridemia [1.3.1].	Gut microbiome modulation [1.3.1].
Amoxicillin	Induced cholesterogenesis (cholesterol production) and increased plasma lipids in animal studies [1.6.1]. Down-regulated HDL [1.3.7].	Increased activity of hepatic HMG-CoA reductase [1.3.7].

Clinical Implications and Management

The link between antibiotics and cholesterol has important clinical implications. For individuals on cholesterol-lowering medications like statins, the introduction of certain antibiotics (e.g., macrolides) could potentially reduce the effectiveness of their primary therapy, leading to an unexpected rise in LDL levels [1.2.3]. This highlights the importance of communication with healthcare providers. If you are taking medication for high cholesterol, always inform your doctor before starting a new antibiotic. They may need to monitor your lipid levels more closely or choose an alternative antibiotic that is less likely to interact [1.7.2]. From a diagnostic standpoint, recent antibiotic use could confound routine cholesterol measurements, potentially leading to temporarily skewed results [1.2.4]. A healthy lifestyle, including a balanced diet and regular exercise, remains the cornerstone of managing cholesterol levels, especially when taking medications that may influence your lipid profile.

Conclusion

The evidence clearly indicates that the answer to 'Can antibiotics raise your cholesterol level?' is a nuanced 'yes, some can.' The disruption of the gut microbiome is the central mechanism driving these changes, affecting everything from intestinal cholesterol absorption to hepatic production [1.4.1, 1.5.1]. While some antibiotics like macrolides and certain fluoroquinolones may increase LDL cholesterol and triglycerides, others like metronidazole and doxycycline have shown the opposite effect [1.3.1, 1.2.4]. This complex interplay emphasizes the critical role of our gut bacteria in overall metabolic health. As research continues to unravel these connections, it reinforces the importance of judicial antibiotic use and open dialogue between patients and healthcare providers about all medications being taken to ensure optimal health outcomes.

For more in-depth information on how various medications can affect lipid levels, you can review resources like the National Center for Biotechnology Information (NCBI) bookshelf. Link

Frequently Asked Questions

Studies have associated macrolides (like azithromycin), lincosamides (clindamycin), and some fluoroquinolones (ciprofloxacin) with an increase in cholesterol or triglycerides. Animal studies also showed amoxicillin can induce cholesterol production [1.3.1, 1.6.1, 1.2.3].

Yes, certain antibiotics like macrolides and clindamycin can interfere with statins. By altering the gut microbiota needed for statin absorption, they may reduce the drug's effectiveness and lead to an increase in LDL cholesterol [1.2.3].

Antibiotics disrupt the gut microbiome, which can increase the intestine's absorption of cholesterol, reduce the recycling of cholesterol-derived bile acids, and in some cases, increase the liver's own production of cholesterol [1.2.1, 1.4.2].

In many cases, the changes are temporary. One study noted that cholesterol elevations that occurred a few days after starting antibiotics were reversible after stopping the medication and allowing the intestinal bacteria to be re-acquired [1.2.1].

No, the effects are highly variable. While some antibiotics may raise cholesterol, others have been found to lower it. For instance, metronidazole and doxycycline have been linked to reductions in cholesterol levels [1.2.4, 1.3.1].

You should inform your prescribing physician that you are on statin therapy. They may choose an antibiotic with a lower risk of interaction, such as azithromycin over clarithromycin, or decide to monitor your cholesterol levels more closely [1.7.2].

Many medications can affect lipid levels, including certain diuretics, beta-blockers, corticosteroids (like prednisone), protease inhibitors used for HIV, and some anticonvulsants and antipsychotics [1.8.3, 1.8.5].