If you’re a fitness fanatic, protein powder is often an essential part of your diet.

But Adam Brenton, 25, says that he recently found a little too much protein in his supplement.

Brenton says that he found a dead mouse in a bag of Myprotein powder…three weeks after he’d first opened the bag. He’d been using the protein powder for the better part of a month when he made the gruesome discovery.

The 1.45 kg bag of protein powder didn’t have any visible bite or claw marks, according to Brenton, and he believes that the rodent had made its way into the container during the manufacturing process. The company that makes the powder has reportedly agreed to take the bag for analysis, but in the meantime, Brenton is demanding some sort of financial compensation.

He says that although he hasn’t gotten sick, his health was put at risk—and naturally, he’s been put off protein powder.

“The mouse must have been buried in the powder and I have slowly revealed it over the three weeks,” Brenton told M.E.N. “I don’t know where in the process it has happened. I just want to be fairly compensated, because my health has been put at risk.”

Myprotein has spoken about to the alleged incident.

“Myprotein treats all customer complaints extremely seriously and is investigating the incident as a matter of urgency,” a company spokesperson told The Sun.

“As with any customer complaint all communications are confidential between Myprotein and the customer, however, we are able to our comment about our manufacturing and quality control standards.”

Athletes often use protein powder to make after-workout drinks to aid in muscle recovery. It’s possible that this mouse wanted to gain more muscle.

These types of bizarre discoveries tend to occur every few months.

In late 2016, Manhattan resident Cailey Fiesel found a mouse sewn into the hemline of a $40 dress she’d purchased from a Connecticut store.

Fiesel said she’d noticed a “disturbingly pungent odor” several weeks after buying the dress while she was wearing it to work.

“I felt something brushing up against my leg and thought it was a string from the seam of the dress,” she told the New York Post.“I then felt the hem of the dress and it felt like there was some sort of sensor. I turned up the seam of the dress and saw it was not a sensor and that it was a mouse.”

“I froze—I was paralyzed with fear,” she said. “I was in complete shock. My eyes saw that it was a mouse, but my brain told myself it can’t be.”

A spokesperson for the company that sold her the dress noted that there was an investigation underway.

The company “has stringent health and safety standards,” the spokesperson said, “and we are committed to ensuring that all of our products meet these rigorous requirements.”

Fiesel is reportedly demanding compensation via a lawsuit, alleging that negligence allowed the rodent to be sewn into the dress.