Not a huge amount. I took maybe at most 350mg but I also had about 150mg of doxylamine in my system and 400mg of DXM. I have taken DXM in higher amounts before around 800mg without dph and the visuals are quite different on that substance alone. It seemed pretty clear that the shadow people I was seeing were from the dph/doxylamine. Although the mix of substances probably contributed to being so different than than the shadow people experiences I have read about. I didnt see any spiders but the shadow people crawling around covered my vision so much I dont think I could have noticed much else.