The Pornstar Martini has been crowned the most hangover-inducing cocktail, according to a new study that ranked classic serves.

The study from online retailer On Buy sought to rank classic cocktails and create a Cocktail Hangover Index.

A survey of 2,892 people tasked participants with scoring each of the 15 cocktails featured on qualities such as resulting headaches, feelings of sickness, or the amount of time wasted in bed the following day.

On Buy asked drinkers to rate 15 classic cocktails including the Sex on the Beach, Cosmopolitan, Bloody Mary, Pornstar Martini, Negroni, Tom Collins, Singapore Sling, Margarita, Tequila Sunrise, Whiskey Sour, Old Fashioned, Piña Colada, Strawberry Daiquiri, Mojito and Long Island Iced Tea.

After rating each drink, the survey found that the Pornstar Martini was the most hangover-inducing, while respondents rating the Mojito as the least.

Click through our gallery to see which cocktails made up the top five most hangover-inducing serves. 

Pornstar Martini

This combination of vanilla vodka, passion fruit and Champagne was given a hangover factor of 7.9 out of 10.

Respondents also ranked it as resulting in the highest average amount of time wasted in bed the following day, at 11 hours.

Sex on the Beach

In second place is the Sex on the Beach, which comprises vodka, peach schnapps and cranberry juice.

The serve was given a hangover factor of 6.9, and was also named the most likely cocktail to make drinkers crave greasy foods.

Long Island Iced Tea

This heady mix of vodka, Tequila, rum, triple sec, gin, and cola was placed third, with a hangover factor score of 6.8 out of 10.

Drinkers said this serve was the most likely to leave them feeling dehydrated the following morning.

Tequila Sunrise

Combining Tequila, orange juice, and grenadine syrup, the Tequila Sunrise was given a hangover factor score of 6.7, placing it in fourth.

The popular serve, which has its origins on the sunny coast of California, was said to leave drinkers craving greasy food while spending an average of 7.3 hours in bed the following day.

Piña Colada

Finally, fifth place was given to tropical classic the Piña Colada, which combines rum, coconut milk and pineapple, and was awarded a hangover factor of six out of 10.

The indulgent cocktail was said to leave drinkers with a headache and could result in them being stuck in bed for 7.2 hours the next morning.