Scientists have found there are ingredients in your smoothie that could be killing you.

According to nonprofit Clean Label Project, some protein powders have high levels of BPA which is found in plastic and heavy metals like lead, mercury, cadmium and arsenic.

These substances have been linked to cancer, brain damage, and reproductive issues, says Consumer Reports.

Clean Label Project tested more than 100 protein powders for over 130 toxins linked to cancer and found that nearly all of them tested positive for at least one heavy metal.

The study tested animal-based, plant-based and whey protein powders. According to Clean Label Project, certified “organic” protein powder products have on average over twice the heavy metals compared to non-organic products tested. And 75 percent of plant-based protein powders tested positive for lead.

Clean Label Project’s test rated these protein powder brands the poorest overall scores:

• Garden of Life

• Nature’s Best

• Quest

• 360Cut

• Vega

If these products could be damaging to your health, some people are questioning if protein powder is even necessary. Well, according to Consumer Reports, the majority of adults get plenty of protein from the foods they eat.