George Huitson said she was “freaked out” after opening the box of her new Oral-B Genius 8000 electric toothbrush last week and finding red smears inside.
Images show what appears to be blood on both the foam packaging and a piece of cardboard where the £100 toothbrush had been placed inside the box.
George returned the item back to the Argos store in Hornsey, north London where she bought it from and claims a staff member said it must have been a return.
The 34-year-old shared an image of the bloodied packaging on Twitter last week, writing: “Hey @OralB just picked up one of your Genius 8000 toothbrushes and there is blood all over the packaging?
Twitter users were shocked by the disgusting discovery.
One said: “Jesus f**king christ, that’s a lot. I had this on an electric razor once and I was nearly sick but it wasn’t that much.”
Another simply wrote: “OMG”
Speaking today, George said: “I bought the toothbrush in Argos on Tuesday and upon bringing it home I started to take the tray out of the box to look at the contents inside.
“I noticed pretty quickly that there were red marks on the side of the box, on the plastic toothbrush carry case and on the plug box.
“I didn’t know what this was at first and thought maybe it was nail varnish, but quickly realised it was blood.
“Obviously, this freaked me out massively as no one wants to open up any product that they’ve purchased to then discover any form of bodily fluids on it, let alone blood.
“I took it back to Argos and they notified me that it may have been sent back and not checked correctly, but they did quickly offer me another toothbrush that same day.
“Either way, it was gross.”
An Argos spokesperson today said: “We have apologised to the customer for this experience and replaced the toothbrush, which she was happy with.”