In 2017, Consumer Reports wrote about a company that made up fake testimonials from Stephen Hawking and Denzel Washington and photo-edited fake covers of National Geographic and Time magazine to tout a brain-boosting product's virtues.

Unfortunately, such wild pitches for unproven brain supplements have not gone away.

A new study published online for the journal Neurology Clinical Practice reveals that mental focus and memory-boosting supplements available in shops and online may contain unapproved pharmaceutical drugs in potentially dangerous combinations and doses.

Five non-approved drugs — sometimes identified on the labels as "nootropics," "smart drugs" or "cognitive enhancers" — as well as drugs that were not mentioned on the labels, were found in the supplements tested.

Say the researchers: "We found doses of unapproved drugs [in amounts] that were as much as four times higher than what would be considered a typical dose."

So stay away from the smart pills. If you want to boost your cognitive powers, use these well-researched, safe techniques:

1. Eat a Mediterranean diet and get a daily dose of omega-3 fatty acids.

2. Aim for 30-60 minutes of exercise at least five days a week. That will promote the release of a hormone that protects you from Alzheimer's, ease symptoms of cognitive impairment, and according to the Cleveland Clinic, "may increase the thickness of the cerebral cortex, improve the integrity of white matter [and] your brain's ability to form new neural connections."

3. Get seven to eight hours of sleep nightly.

4. Play speed-of-processing games that promote brain agility.

5. Manage your stress response with meditation, exercise, and maybe some talk therapy.