For investors seeking stocks to put into their portfolios for the long term, healthcare's a great place to look. It's an industry where there's always going to be significant demand, especially as the population ages. Drug manufacturers AbbVie (ABBV 0.40%) and Biogen (BIIB 0.17%) are two of the bigger names in the industry, and their stocks offer investors two enticing approaches: one that's focused on growth, and another that's centered around stability and recurring income. Let's take a look at which is the better option today.

Is Biogen too volatile?

To say that Biogen's stock price has been unstable over the past year would be an understatement. Over the past 52 weeks, the drug manufacturer's stock has traded within a wide range of $215 to $375. Although it's technically down 18% since March 1, 2019, that number doesn't tell investors the full story. About a year ago, the company's stock went over a cliff, falling from $320 down to a low of about $215 after Biogen said it was going to scrap drug trials related to aducanumab, which treats Alzheimer's.

Then, in October, the company revived the drug, saying it was going to seek approval from U.S. regulators after collecting more data which showed the drug was making progress in fighting the disease after all. Shares popped, rising from about $220 to over $300 in the days following the news.

People working in a lab.

Image source: Getty Images.

Last month, Biogen's stock price got another boost when investors learned that Mylan (MYL) had been unsuccessful in its patent challenge against Biogen's multiple sclerosis drug, Tecfidera. Biogen's stock is down 19% over the past month; the company has been unable to avoid the market's recent instability around rising concerns surrounding the spread of COVID-19. That said, it's ahead of the S&P 500, which is down 31% over the same time. 

Biogen's stock isn't for the faint of heart. But the good news is that the company's consistently stayed in the black, with its profit margin remaining above 20% in each of the past 10 years.

It's an impressive feat, especially amid strong growth. From $4.7 billion in revenue in 2010, Biogen's sales reached $14.4 billion this past year. In 2019, its annual growth rate was a solid 6.9% from 2018's tally of $13.5 billion. Despite the strong numbers, Biogen still trades for less than 10 times its earnings. 

Does the acquisition of Allergan make AbbVie a stronger buy?

On its own, AbbVie is a solid healthcare stock; its strong, consistent revenue has topped $30 billion for the past two years. It also pays a dividend that has increased for more than 40 consecutive years (counting the time it spent as part of Abbott Laboratories (ABT -0.65%)), making it a Dividend Aristocrat. Currently, it pays a quarterly dividend of $1.18 per share, which yields an impressive 6.8% today. Biogen doesn't pay its shareholders a dividend.

The problem for AbbVie is that in its most recent fiscal year, it generated sales growth of just 1.6%. That's where it needs something to jump-start its growth -- and its $63 billion acquisition of Allergan (AGN) could play a big part in that. The deal, which the companies expect will close in May of this year, will give AbbVie access to Botox, which was Allergan's top-selling drug in 2019, generating $3.8 billion in revenue. 

While it's a good addition, Allergan hasn't been blowing the doors off its revenue numbers, either. In 2019, revenue totaled $16.1 billion, which was just a 1.9% improvement from the previous year. Even with the acquisition, there may not be sufficient growth in AbbVie to make the investment attractive for investors who are looking for more than just value.

AbbVie is the safer buy, but growth investors may opt for Biogen

A quick look at how these two stocks have performed over the past year shows little difference, despite their very different paths along the way:

ABBV Chart

ABBV data by YCharts.

Deciding between these two stocks ultimately comes down to your investing approach. If you're a value-oriented investor who is risk-averse, then AbbVie, with its impressive dividend, is a solid pick. The stock trades at a very reasonable 12 times earnings, which is only slightly higher than Biogen's price. In addition, AbbVie can be a solid long-term pick for investors looking to benefit from a growing dividend. But investors who aren't so risk-averse may be willing to take a chance on Biogen, especially in light of the positive developments that have taken place over the past six months.