Personal ads on Craigslist and Locanto are offering much more than the dating cliches of longs walks on the beach and great senses of humour, with drugs including mdma, marijuana and methamphetamine all proffered.

In the past two months, 31 posts from Wollongong to Nowra have offered marijuana and 19 have offered methamphetamine under the commonly used street names "420" and "sweet puff" ostensibly to avoid suspicion.

One advertisement placed on April 28 titled "Looking for teen girls will reward for fun" targeted young female drug users, offering "rewards or puff or both" in return for "fun".

The poster, listed as a 30-year-old Wollongong man, said "younger slim girls" were preferred and this was "something I've had on my mind for a while and wouldn't mind trying out :)."

A North Wollongong-based poster promised beer, "sweet puff" and marijuana for "adult naughty fun all night" in his hotel room for partners who fulfilled the mandatory requirements of "ONLY YOUNG GIRLS PLEASE!"

One 29-year-old claiming to have finished work early was after "a nice, friendly, young clean sexy girl to have smoke, chill, hang, get high and hot adult x-retaed (sic) fun all night" to share his "5 star apartment".

According to criminal lawyer Aaron Kernaghan, mixing drugs with sex could cause complicated legal ramifications if posters were caught - even if cash didn't change hands during the drug deal.

"It causes a couple of problems particularly around potential solicitation and supply which includes agreeing to supply, offering or keeping drugs for the purpose of supply with, or without, the exchange for money," he said.

Due to the perceived exploitation of targeting drugs users, courts could be particularly hard on those found to be trading drugs for sex.

"Courts could treat supply in exchange for sex in a worse category because you're exploiting people sexually and exploiting drug habits," he said.

"That would likely bring greater condemnation above and beyond the usual sentence."

Allegations of rape could also arise in situations involving sex and drugs, warned Mr Kernaghan, when one party could be too affected by substances to have consenting sex.

"From a legal point of view you wouldn't want to be mixing drugs and sex because, in regards to sex crime, the issue of consent might arise when drugs are present in a situation," he said.

The majority of posters offering the trades were male and aged between 26 and 38. However, one post from three women in their twenties sought out ice in a "sweet puff and play" exchange.

Numerous "men seeking men" posts preferred "420 friendly" casual sex partners.

One couple offered marijuana and ice in a "shout out to all the sexy females that like to puff and play, we have plenty to share."

Not all posts seek trades, with plenty using the personals section to advertise their wares and some even offer delivery.

"Got a little bit of 420 that the easter bunny forgot to eat today so we thought we would hit the road and help put some holidayers with a courier service," read one ad which was titled "Mobile 420 unit".

Others tried to undercut each other on prices, advertising a gram of methamphetamine for $400-$450 for "high quality product" with the aim of retaining "loyal return customers".

One upset buyer registered a consumer complaint after receiving faulty goods.

"If you looking (sic) to get sweet puff don't go to (seller number).. sells you bath salts, he will rip you off."

Lake Illawarra Area Commander Superintendent Wayne Starling confirmed police intelligence were aware of the website.

The frequent ads coincide with the spread of methamphetamine use in the Illawarra, according to Watershed chief executive Will Temple.

"There has definitely been an increase and what we're noticing is existing drug users who are older are switching to ice because it's cheaper and easier to get a hold of."

Mr Temple said in his experience drug users often turned to sex work to support their addiction.