Managing director Wendy Allison told NZME "we've had not seen anywhere near as much n-ethylpentylone as we were expecting to see" in 400 tests done over the New Year period.
"It's hard to say if that means that n-ethylpentylone is on the way out or if it's just at the moment, in the market, there isn't any but we hardly saw it over the New Year and that's unusual ... It's good news if it is going out because it is a nasty little drug."
She said bath salts had been responsible for hospitalisations in New Zealand.
"We've been seeing n-ethylpentylone around in significant quantities for the last two years and all of our testing leading up to the start of the festival season suggested that it was still around but then our testing over New Year's has revealed hardly any."
She said the three teams using spectrometers at various events saw "a lot of MDMA (methylenedioxymethamphetamine)".
"While the vast majority of it is actually MDMA, which is good news in terms of reducing harm, we have also seen a significant number of pressed pills with two and up to three doses of MDMA in them ...
"The high dose MDMA is very, very risky. It could kill you."
That prompted the group to issue a public warning about certain pressed pills on December 30.
Because of current laws, the group cannot say where it has tested or will be testing.
"If people are intending to take illicit substances and they haven't been able to get them tested, our advice for those people is to take a third or less than you would normally take."
Allison said users should also wait at least an hour to see what happens before taking any more "incrementally".
"Once you've taken 300mg you cannot untake them. Whereas if you take it in fractions, you are much more likely to be able to stop before you get into trouble ...
"Make sure someone knows what you are doing and can take you to the medics if you get in trouble."
She said it was much safer for people to be taking MDMA proven to be MDMA "than taking n-ethylpentylone thinking they've got MDMA and coming to harm because of it."
Know Your Stuff NZ's December 30 warning listed the pressed pills shown to contain high-dose MDMA in their recent testing.
That included blue or yellow round pills pressed with the New Yorker symbol, around 370mg in weight, that were estimated to contain 250-300mg MDMA.
Others were white 450mg rectangular pills pressed with the CNN logo, round pink pills pressed with the Mitsubishi logo, light blue triangular pills with the Punisher logo, and bright yellow oval pills with the Ironman symbol on them.
"There are two other examples that we have reports of, that are suspected to be high dose, but we haven't actually yet had a chance to test, confirm and photograph them," Allison said.
"These are pills with a Lego logo and the other has the Tesla logo."
She could not confirm whether staff were testing at Bay Dreams today, but said all but one of the volunteer testing teams had returned home after testing over the last week.
"It's one of those unfortunate situations. The thing is as soon as we get some legal clarity on this, and we are able to start telling people where we are going we will be very open about where we are.
"But at the moment we just have to respect the privacy of the event organisers who are taking the risk to get us there."
Bay Dreams promoter Mitch Lowe said drug testing was something his team had wanted since the festival began but was still not able to happen.
"It's a case of what is legal and what stakeholders would support but it is something we have been pushing for four years.
"We have seen it work overseas so it is not a case of us not wanting it but something that just hasn't aligned yet, but we think soon it will."
A Bay of Plenty District Health Board spokesman said shortly after 5pm that emergency department staff had not seen anything abnormal in terms of numbers or drug-related admissions that day, including from the festival.