Quote from Mullemulle >>

No. It is not. Philter of Love is essentially the "Charm Person Spell". And that states that the effect ends if the charmer or his compagnions do anything to the charmed person that this person sees as negative. 

 
There is nothing in the rules that suggests to me the Philter of Love’s effects should end if the charmer does something that the charmed person would ordinarily find objectionable or even harmful.

“Charmed” is a condition much like “frightened” or “poisoned”, so has set effects on a creature.  Each spell or item that can cause the charmed condition has its own rules about how to counter it independent of how other spells or items behave.  Charm Person is only a first level spell so it has a lot of limitations.

Obviously any DM may rule that the Philter of Love is not powerful enough to keep someone charmed if the charmer does them harm, but that’s not RAW.  If it’s powerful enough to make someone fall in love (for an hour, anyway), it seems inconsistent to make it so easily countered.

Quote from aceovjacks >>

 does anyone know if the person knows they were drugged when the thing wears off?

 
Nothing in the rules to say the person would know they were charmed if they weren’t aware they took the potion.  But you could make it interesting by letting the character roll a Wisdom check when the potion wears off.  It’s very plausible that a shrewd character would notice how suspicious it is that they suddenly had a lot of affection for someone and those feelings evaporated after only an hour.

Says 1 hour

I love that there isn't even a saving throw

 Hey, no spoilers

for the girl who has this type of romantic potion inside her blood where shed find everyone attractive find an npc or player character that accidentally bites her (i'm guessing the characters a girl) like someone recently turned vampire so in a non control of his feelings he bites her then they both love eachother, only he doesnt want to be a vampire so hed have to both resist blood and his new love for her from the love blood effect. and this would get her to be not attracted to everyone but him, and he her. He'd have to be a stronger vampire for not feeding on her and because it mentions species and gender she finally can focus on someone instead of being used by everyone.