If Walgreens Boots Alliance follows through with a sale to private equity, the company might join other healthcare deals under scrutiny for selling out to such investors.

The pharmacy mega-giant shot up 18% on Tuesday following The Wall Street Journal's report, raising the company's value by about $1.5 billion.

Deal would cap tumultuous run for retailer whose market value shrank from a peak of over $100 billion to below $8 billion.