Philip Morris International (NYSE:PM) stock has taken investors on a roller-coaster ride over the past few years. After the company seemingly overcame some fundamental challenges, its share price rose by 50% between mid-2015 and the summer of 2017. But in the year since, the tobacco giant has given back all of those gains. Some of those declines  stemmed from general uncertainty throughout the stock market, but there are also some company-specific issues Philip Morris will have to deal with before its share price can bounce back. Three problems in particular loom ahead, and shareholders should be fearful of what could happen if the company can't address them adequately.

1. A potential price war for heat-not-burn  products in Japan

The key to Philip Morris International's success from 2015 to 2017 was its iQOS heated-tobacco system. The company billed the heat-not-burn tobacco product as the initial step in a transformation of its business model, and asserted that it could foresee a future in which it no longer sold traditional cigarettes at all. Quarter after quarter, adoption rates in its initial test market of Japan were extremely strong, and that made investors optimistic about iQOS's chances of replacing cigarettes entirely.

Yet competition has finally come to Japan's heated-tobacco market, and that's weighing on Philip Morris' profit potential. Japan Tobacco makes a rival set of heat-not-burn products, and in the wake of a 30% reduction on the iQOS put in place late last week, JT announced that it's looking to cut prices on its system by 25%. The Glo system from British American Tobacco is currently available at a 50% discount in a promotion that's expected to run through the rest of 2018, undercutting both other products. Even if the overall heated-tobacco market in the country keeps growing, it'll be tough for Philip Morris to retain market share.

Two hands holding a white iQOS heated-tobacco device.

Image source: Philip Morris International.

2. The strong dollar is back

Philip Morris had to deal with intense headwinds from weak foreign currencies in past years, because while it is a U.S. company, it does all of its business overseas. When local currencies are weak, sales in those markets translate into fewer dollars, hurting revenue and profit. Over the past year, it had looked like the dollar was finally starting to weaken, which would have given PMI's financial results a long-awaited boost.

Yet the recent hikes in U.S. benchmark interest rates have combined with rising fears of a global economic slowdown to send the dollar back up to levels it hadn't seen in almost a year. The euro has been especially weak, and given that Philip Morris does a lot of business in Europe, if the regional currency doesn't reverse course and start to strengthen again, the company could take a hit on its top and bottom lines.

3. FDA regulation could get a lot more intense

Philip Morris had hoped that the Food and Drug Administration would be sympathetic to its strategy, and quickly approve iQOS for the U.S. market in an effort to shift smokers toward what it asserts is a reduced-risk alternative. Yet so far, regulators appear to be growing more averse to cigarette alternatives rather than less. The FDA's warnings about sales of JUUL-branded electronic cigarettes to underage customers have put the industry on notice that regulation of alternative tobacco products won't be any more lenient than it has been for traditional tobacco products.

Meanwhile, Philip Morris hasn't seen much movement on its modified-risk application for the iQOS in the U.S. market, which suggests that it could take longer than investors had hoped to navigate the process -- and with no clarity of getting the hoped-for result. With the FDA looking to regulate nicotine levels in all tobacco-related products, Philip Morris could face a new obstacle that may prevent it entirely from realizing its vision for the U.S. market.

Keep watching

There are plenty of good things happening for Philip Morris, and these three trouble spots won't doom the company. However, investors in search of potential growth catalysts for its profits and its share price will want to keep a close eye on how these issues play out.