How should I schedule my medications and supplements (psyllium fiber, isotretinoin, S‑acetyl‑glutathione, prebiotic/probiotic, vitamin C (ascorbic acid) and zinc, rosuvastatin, berberine) relative to meals?

Medication and Supplement Timing Schedule

Take isotretinoin and rosuvastatin with your largest meal, psyllium fiber separated by at least 2 hours from all other medications, and berberine with meals to optimize absorption and minimize drug interactions.

Morning (Fasting)

Rosuvastatin

• Take at any time of day, with or without food 1
• However, if taking with isotretinoin, coordinate both with your largest meal for optimal isotretinoin absorption 2
• Separate from antacids (aluminum/magnesium hydroxide) by at least 2 hours 1

With Largest Meal (Breakfast, Lunch, or Dinner)

Isotretinoin (CRITICAL TIMING)

• Must be taken with food—this is non-negotiable 2
• Taking without food significantly decreases absorption 2
• Divide total daily dose into two administrations with meals 2
• Failure to take with food is a common pitfall that reduces drug efficacy 2

Berberine

• Take with meals to enhance absorption and reduce gastrointestinal side effects (similar to metformin's meal-timing recommendations) 3
• Can be split across multiple meals if taking higher doses

S-Acetyl-Glutathione

• No specific meal timing required based on safety data 4
• Can be taken with meals for convenience and to minimize potential gastric upset

Vitamin C and Zinc

• Take with food to reduce gastric irritation
• No specific separation from other supplements required

Between Meals (At Least 2 Hours Before or After Other Medications)

Psyllium Fiber (CRITICAL SEPARATION)

• Take at least 2 hours before or 4-6 hours after all other medications 5
• Psyllium can bind to medications and reduce their absorption (similar mechanism to bile acid sequestrants) 5
• Best taken mid-morning or mid-afternoon, away from meal-associated medications
• Ensure adequate water intake (at least 8 oz) to prevent esophageal obstruction 6

Flexible Timing (Any Time of Day)

Prebiotics and Probiotics

• Can be taken with or without food
• Consider taking with psyllium fiber (when separated from other medications) as psyllium acts as a prebiotic and enhances probiotic survival 7, 8
• If taking psyllium separately, coordinate probiotic timing with it for synergistic benefit 7

Practical Daily Schedule Example

7:00 AM - Rosuvastatin (if not taking with largest meal)

9:00 AM - Psyllium fiber + Prebiotics/Probiotics (2+ hours before lunch medications)

12:00 PM (Lunch - if this is your largest meal)

• Isotretinoin (first dose)
• Berberine
• S-Acetyl-Glutathione
• Vitamin C and Zinc
• Rosuvastatin (if coordinating with isotretinoin)

3:00 PM - Alternative timing for psyllium if not taken in morning

6:00 PM (Dinner)

• Isotretinoin (second dose)
• Berberine (if splitting dose)

Critical Warnings and Pitfalls

• Never take isotretinoin on an empty stomach—this is the most common error that significantly reduces drug levels 2
• Do not take psyllium within 2 hours of any medication—it can bind drugs and reduce absorption 5
• Avoid taking multiple medications together in the fasting state, as gastric juice-resistant formulations may accumulate and empty unpredictably 9
• If you experience gastrointestinal side effects from berberine, take it 15 minutes after starting your meal (similar to metformin guidance) 3