Editor's pick: Originally published Jan. 4.

Small investment ideas can sometimes offer a powerful boost to your portfolio. While they may lack the glitz of the bigger players, these stocks can deliver a strong foundation and long-standing value.

Here are three health care stocks that have largely zipped over the heads of Wall Street analysts. They might seem a little riskier in addition to being unknown, but we believe they've got great times ahead of them.

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1. PetMed Express (PETS - Get Report)

PetMed Express is a nationwide pet pharmacy. The company markets prescription and nonprescription pet medications and other health products (for dogs, cats, and horses, among other animals) directly to the consumer.

Analysts suggest that the company should post an earnings per share upswing this fiscal year (which ends March 2016). Over the next five years, EPS growth is estimated to clock in at an average of 5% per year, running at a pace similar to that of the S&P 500.

The company's superior operating margins -- at nearly 14% (vs. 4.3% for the industry) -- is a clear indicator of its core strengths and capacities.

Despite a year-over-year decline in net sales, the company was able to boost gross profit margins and average ticket size in its fiscal second quarter. This helped it record net income of $4.5 million, up 65% year over year.

Going forward, we believe the American consumer will increasingly use online channels/modes to order pet medicines. PetMed is smartly positioned in this segment as well.

Granted, this is a niche business model, but given the competitive nature of the industry, PetMed's Web site channel is its biggest revenue generator, accounting for more than 81% of sales.

What's just as impressive is that the company has zero debt. Additionally, PetMed is crafting a bold attempt towards shifting to higher margin items including private label. The low-margin business (flea and tick topical) is too commoditized.

PetMed is focusing on enhancing its marketing efforts, thereby driving sales and profitability. The company offers an attractive dividend yield of 4.20%. The stock currently trades at 17 times forward earnings.

Unlike several overvalued stocks ripe for a fall right now, PetMed won't disappoint in 2016.

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2. Meridian Bioscience (VIVO - Get Report)

Meridian Bioscience is an integrated life science entity, involved in the complete diagnostic test kit product development lifecycle. The key applications are for certain strains of viral, respiratory, gastrointestinal and parasitic infectious diseases.

Diagnostics accounts for a majority of its sales. While three-year revenue and net income growth figures are currently behind the industry average, the company boasts of an operating margin of 28.8%, more than double the industry standard.

Analysts suggest sales should grow by nearly 3% next year (September 2017) after inching up by 1.6% (September 2016). EPS growth is slated to hover around the 3.5% range for this year as well as the next.

Investment experts predict a 16% EPS growth for Meridian each year for the next five years.

Like PetMed, Meridian has zero debt. Of late, Meridian has exhibited its ability to maintain relevance and fortify core capabilities -- 2015 showed that the company has what it takes to stay its ground in a highly competitive industry.

Meridian has continuously improved its free cash flow per share over the years, another positive, underlying the company's inherent stability. The stock trades at 23.3 times forward earnings and has a yield of 3.90%.

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3. Amphastar Pharmaceuticals (AMPH - Get Report)

Amphastar Pharmaceuticals is a specialty pharmaceutical company. It develops, manufactures, markets and sells generic and proprietary injectable and inhalation products. In 2014, the company commenced sales of insulin active pharmaceutical ingredient products.

The company has a superior three-year average revenue growth of 21.2% vs. the industry's 17.7%.

Analysts offering 12-month price targets for Amphastar Pharmaceuticals have a median target of $19.50, suggesting the stock can gain nearly 40% from recent levels. After losses this year (December 15), the company is projected to post a marginal profit next year accompanied by more than 12% top-line growth.

Apart from its existing medicines, the company currently has three abbreviated new drug applications, or ANDAs, filed with the FDA for target products with a market size of over $500 million. Its arsenal also boasts of another 11 generic products in development.

Meanwhile, certain vulnerable stocks are bad choices. They're ridiculously overvalued with weak fundamentals, which is a terrible combination under any circumstances. For a list of the worst stocks to own now, click here.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.