 Which stocks tend to polarize market watchers? Penny stocks. Out on Wall Street, investors have strong opinions when it comes to these divisive tickers, which trade for less than 5 per share.The penny stock critics make valid points when defending their stance. Sure, the price tag may look like a steal, but the fact that shares are trading at such low levels could reflect overwhelming headwinds or weak fundamentals.That being said, the fans offer up a solid argument as well. Not only does the low price mean you get more shares for your money, but hefty returns are also on the table. Even seemingly insignificant share price appreciation can result in colossal percentage gains that other more well-known or expensive names arent as likely to deliver.The nature of these investments presents somewhat of a dilemma. How are investors supposed to separate the penny stocks that are ready to take off on an upward trajectory from those set to remain down in the dumps?To help with the due diligence process, we used TipRanks database to zero in on only the penny stocks that have received bullish support from the analyst community. We found three inhabiting the healthcare sector that are backed by enough analysts to earn a Strong Buy consensus rating. Not to mention each offers outsized upside potential.Clearside Biomedical CLSDUsing its patented SCS Microinjector that targets the suprachoroidal space SCS, Clearside Biomedical develops treatments that could potentially be capable of restoring and preserving vision for people with serious back of the eye diseases. Given the strength of its platform and its 1.91 share price, several members of the Street believe that now is the time to pull the trigger.Representing Roth Capital, analyst Zegbeh Jallah cites its technology as a key component of his bullish thesis, calling the platform undervalued. The microinjector is able to inject fluid into the SCS, which is between the choroid and sclera, so it can be effectively absorbed by adjacent tissues. This is important as it reduces off-target delivery.To provide evidence of the devices efficacy, Jallah points to the clinical data from the pivotal studies evaluating XIPERE, its first drug using the microinjector. The potential of Clearsides proprietary SCS microinjector to limit off-target delivery was evident by the lower rates of elevated IOP in patients treated with SC-injected triamcinolone due to lower concentrations of the drug flowing into the anterior chamber, the analyst commented.According to Jallah, this makes it very likely that the therapy will get the FDAs stamp of approval in mid-2021 after the company resubmits the NDA by year end 2020. It should be noted that XIPERE is currently licensed to Bausch and Artic Vision, with CLSD also finalizing a licensing agreement with Aura in July 2019 and REGENXBIO in August 2019. The analyst argues these agreements highlight the attractiveness of Clearsides SCS microinjector.Looking specifically at the REGENXBIO partnership, Jallah stated, Despite some loss of that momentum due to the pandemic and the announced pushback of XIPEREs NDA resubmission date, we are bullish that promising data from the planned Phase 2 study by REGENXBIO, and Clearsides planned Phase 1 study of suprachoroidal delivery of axitinib CLS-AX for wet AMD, which could provide significant upside to Clearsides valuation, and make it a strong MA; target.To this end, Jallah rates CLSD a Buy, while setting an 8 price target. This target suggests shares could soar 319 in the next year. To watch Jallahs track record, click hereDo other analysts agree with Jallah? As it turns out, most do. 3 Buy ratings and a single Hold add up to a Strong Buy analyst consensus. At 6.33, the average price target indicates 231 upside potential. See Clearside stock analysis on TipRanksProteostasis Therapeutics PTIProteostasis Therapeutics is developing CFTR modulator combinations to provide more drug options for people with cystic fibrosis CF. As the company gears up for the release of clinical data in Q1 2021, some analysts believe that at 1.38 per share, its price tag reflects an attractive entry point. Writing for Cantor, analyst Kristen Kluska tells clients that PTI completed enrollment and collected rectal biopsies for the CHOICES study, which features patients with ultra-rare cystic fibrosis mutations, before COVID-19 started causing delays. Currently, samples are being stored in liquid nitrogen until the company can conduct the ex vivo testing, which may take a few weeks, and the organoids are being tested in four labs in Europe.Kluska noted, Proteostasis is in weekly engagement with centers, and notes that timelines remain on track at this time... From our calculation, we think these timelines assume that labs will be able to re-open and complete the analysis by or around August.Additionally, Kluska points out that data in Q1 2021 may include ppFEV1, sweat chloride and safety measures. Expounding on the implications of the data readout, she said, We think this will be a major catalyst for PTI considering results could help frame whether these assays are predictive in determining who best responds to PTI drugs which could ultimately frame the basis for utilizing the personalized medicine approach across the MORE trial, which patients, physicians and regulators have encouraged.The readout will also represent the first look at the triplet data beyond 28 days, which unlike the doublet, kept demonstrating an increased benefit in ppFEV1. We think a trial double in length of eight weeks will provide more context on the amplifiers potential. Additionally, we believe there is a lower bar for efficacy for the ultra-rate mutation population as patients are ineligible for all approved modulators, and results could help explain how many patients show some level of benefit, Kluska stated.With its 57.1 million in cash expected to support the companys operations into 2H21, the deal is sealed for Kluska. In line with her optimistic take, she reiterated an Overweight rating and 4 price target. Should the target be met, a twelve-month gain of 190 could be in store. To watch Kluskas track record, click here Looking at the consensus breakdown, other analysts are on the same page. With 4 Buys and no Holds or Sells, the word on the Street is that PTI is a Strong Buy. The 5.50 average price target puts the upside potential at 299. See Proteostasis stock analysis on TipRanksExicure, Inc. XCURExicure develops a new class of immunomodulatory and gene regulating drugs that feature its spherical nucleic acid SNA architecture designed to unlock the potential of therapeutic oligonucleotides in a range of cells and tissues. Currently going for 2.72 apiece, the pros on the Street think that the share price presents investors with a unique buying opportunity.Part of the excitement surrounding XCUR is related to its Phase 2 dose expansion evaluating AST-008 in patients with advanced or metastatic Merkel cell carcinoma MCC or cutaneous squamous cell carcinoma CSCC who have progressed on a single-agent checkpoint therapy. The therapy will be used in combination with pembrolizumab in MCC or cemiplimab for CSCC. With trial sites already open and enrollment kicking off during Q2 2020, focus has locked in on XCUR ahead of its presentation of updated PD and safety data on AST-008 alone and in combination with pembrolizumab at the AACR meeting on June 22-24.Among the bulls is Ladenburg analyst Wangzhi Li. He tells clients the good news extends beyond AST-008s Phase 2 trial. IND-enabling studies of XCUR-FXN in Friedreichs Ataxia FA, a rare autosomal recessive disorder that causes neural degeneration, especially affecting neural-muscular control, are expected to begin this calendar year. Given that theres an estimated 5,000 patients in the U.S. and 15,000 patients worldwide suffering from FA and there arent any FDA-approved treatments, Li argues the therapys potential is significant.We see FA as an attractive indication for SNA, given SNAs broad and extended distribution in brain and spine shown in prior studies. Exicure is also exploring additional neurological conditions, including spinocerebellar ataxia, Batten disease, amyotrophic lateral sclerosis ALS and Huntingtons disease, Li explained. He also points out that XCUR will partner with Friedreichs Ataxia Research Alliance FARA to advance the program.If that wasnt enough, XCUR is collaborating with Allergan on an SNA treatment from two programs for hair loss disorders. As per the terms of the deal, XCUR will screen and identify SNA candidates against selected targets for treating hair loss, and Allergan will pay XCUR 25 million upfront, up to 725 million in milestones and mid-single digit to mid-teens royalties. In addition, preclinical RD; activities for XCURs collaboration with Dermelix for Netherton Syndrome NS are progressing right on track.Based on all of the above, its no wonder Li reiterated his Buy recommendation. With an 18 price target, shares could climb 562 higher in the next twelve months. To watch Lis track record, click here Like Li, other analysts also take a bullish approach. XCURs Strong Buy consensus rating breaks down into 4 Buys and zero Holds or Sells. Given the 10 average price target, the upside potential lands at 268. See Exicure stock analysis on TipRanksTo find good ideas for healthcare stocks trading at attractive valuations, visit TipRanks Best Stocks to Buy, a newly launched tool that unites all of TipRanks equity insights. 