Three students believe they were spiked by injection on a night out leaving them completely wiped out, sweating excessively and with bruises on their arms.
The women, two aged 19 and one 20, were out with friends in the Gay Village area of Birmingham when they say they were targeted.
One of the trio, who suffers with health anxiety, described the experience on Friday night as "traumatising".
The student said her "heart dropped" as she says she later discovered a pin prick hole in the arm of her leather jacket.
The three friends, who had been part of a seven-strong group, said they were forced to visit A&E for blood tests and Hepatitis jabs amid the scare.
"It felt like quite a unique experience because it's not like I noticed anything different," one of the students, who did not wish to be named, told Birmingham Live.
"My night was pretty normal, until the morning I felt I'd got a bruise on my arm."
A friend then explained how she felt she had been 'spiked on the night out', but "couldn't remember a thing".
She was the first to visit A&E and report she had been spiked to the hospital staff.
The student added: "She wasn't unconscious or anything but she was acting out of character.
"Usually, she's bubbly, kind, never starts an argument. She was getting quite argumentative and running away.
"She couldn't remember anything she had done, people were telling her things she'd done on the night and she couldn't recall any of it, which is unlike her. We all felt awful but we thought: 'Maybe it's just a hangover'.
"The entire day was wiped out, I was exhausted and excessively sweating, it was like cold sweats and I was constantly sleeping. I felt really weak, my arm was killing me. I dismissed it as if I'd accidentally bruised it because I didn't black out."
Her friend later called to tell her a second pal had also discovered a bruise on her arm. And on closer inspection of her own bruise, she found a mark "where a pin prick could have been".
"I was so confused because I was wearing a jacket the entire night. So then I looked through my jacket and I found a pin prick hole where my bruise was in the jacket - my heart just dropped," she added.
"Before I was invalidating it a bit because I hadn't had the experience of feeling out of it. My arm had been hurting all day but I just dismissed it. I have quite bad heath anxiety so this is literally traumatising."
The two friends travelled to A&E at the Queen Elizabeth Hospital in the city.
She added: "I got my Hep B jab on the other arm, but my spiked arm is hurting more than it has been for the past two days. That's how I definitely know it's a spike mark, it would be better by now if it was just a bruise.
"Both my friends didn't know they had been injected until the next day, which is terrifying. When I spoke to the people at A&E they said: 'Most shifts there is at least one person that comes in', I was like: 'That is awful, why is nothing being done about this?'"
West Midlands Police said it had launched an investigation after the three friends reported the incident to the force.
A statement from West Midlands Police read: "We’re investigating a report of three women being spiked during a night out in Birmingham city centre on Friday (February 18).
"The women – who are friends - all noticed bruising to their arms the following day. They also could not recall events from the previous evening.
"This led them to believe they had been spiked and report this to us. Further enquiries will be carried out.
"For more information about staying safe on a night out visit https://west-midlands.police.uk/campaigns/safer-nights."
