I accidentally left my bottle of Latisse in my suitcase in a hot car for 5-7 hours. Did I ruin its effectiveness?

Hi there,You have nothing to worry and your latisse should be fine and you can still use it! Studies are out to support this as stated.

You should be fine as their is no scientific evidence to suggest otherwise. Enjoy your lashes! 

Thank you for your question. There is no evidence that temperature change effects Latisse so your bottle should be fine. Best of luck, Dr. Heffernan

All studies to date would suggest the Latisse is fine. A 2011 study by Johnson and colleagues looked at how the concentration of Latisse (and other prostaglandins) changed when exposed to elevated temperatures including 37 C and 50 C for 3, 6,9, 15 or 30 days. Interestingly there was no change in the concentration of Latisse over time. Of course if your Latisse reached even higher temperatures, we enter a grey area and don't fully know the answer. However Latisse can withstand quite a bit of heat due to its remarkable thermable stability.



Reference 
Thermal stability of bimatoprost, latanoprost, and travoprost under simulated daily use.
Johnson TV, et al. J Ocul Pharmacol Ther. 2011.

The studies support that latisse should be fine even when exposed to hot temperatures as in a parked car.

As long as your vial of Latisse had the cap on, studies show a very low rate of degradation (over a period of days, not hours) and then only at very high temperatures (over 50 degrees C). If the cap was off, then some of the product may have evaporated, so the remaining Latisse will be more concentrated. This would NOT hurt its effectiveness, and may even make it stronger!