I had been using passionflower extract at 400mg for sleep with good results for about a month. Being the kind of person who always wonders "what if I took more," I decided to try 1000mg on a Saturday afternoon with nothing planned.
T+0:00 — Took four 250mg capsules with water after a light lunch.
T+0:45 — First effects. Noticeably more sedating than my usual 400mg dose. A heaviness in my eyelids that was hard to fight. The anxiolytic effect was present but not dramatically stronger than my normal dose — maybe 20% more pronounced.
T+1:30 — This is where it became unpleasant. I was drowsy to the point of feeling drugged, but not in a comfortable or relaxing way. There was a mild dizziness when I stood up — not vertigo, but a slight delay between moving my head and my visual field catching up. Mild nausea settled in. I felt confused in a low-grade way, like I was thinking through gauze.
T+2:00 — I lay down on the couch and fell asleep for 3 hours. Not intentionally — I simply could not stay awake. Woke up at 5 PM feeling groggy, disoriented, and slightly headachy.
T+4:00 — Effects mostly resolved. The grogginess lingered into the evening and I went to bed early.
The lesson: passionflower has a ceiling of useful effects. The anxiolytic benefit does not scale linearly with dose — it plateaus somewhere around 400-500mg for me. Beyond that, you are just adding sedation, dizziness, and confusion without meaningfully more calm. It is not dangerous (I never felt unsafe), but it is pointless and unpleasant. My regular 400mg dose is objectively more useful and more pleasant than double or triple that amount.
Stick to the recommended range. The people who standardized these doses knew what they were doing.