United Therapeutics is a biotechnology company. It is listed on the NASDAQ. Its headquarters are located in Silver Spring, Maryland, with additional facilities in Research Triangle Park, North Carolina; Magog, Quebec; Melbourne, Florida; and Manchester, New Hampshire.

United Therapeutics was founded in 1996 by Martine Rothblatt, an American lawyer, author, and entrepreneur, who previously created Sirius XM. In 1994, Rothblatt's young daughter was diagnosed with a fatal orphan disease, pulmonary arterial hypertension (PAH). Rothblatt sold her telecom stock and started the $3 million PPH Cure Foundation to fund PAH research. By 2002 the FDA had approved United Therapeutics new drug Remodulin an alternative to GlaxoSmithKline's Flolan. In 2002 Remodulin was priced at $90,000 per year and within "a year annual sales were $50 million." By 2010 sales rose to $300 million.

By 2010 "United Therapeutics shares had increased 800% from 1999 when the company went public.

By October 2012, United Therapeutics had a market capitalization of US$3 billion. Rothblatt received a total compensation of $31,581,896 in 2014. According to the "annual collaborative report" from Equilar and The New York Times, Rothblatt ranked 24th in the list of "200 highest-paid CEOs of large publicly traded companies" and fourth in the list of biopharmaceutical executives with the highest total compensation.

On December 31, 2014, United Therapeutics announced a deal with DEKA, for the development of a potential technology breakthrough in the subcutaneous delivery of its Remodulin (treprostinil) injection to patients with pulmonary arterial hypertension (PAH) via a pre-filled semi-disposable pump system. According to Martine Rothblatt, “The new DEKA semi-disposable pump system will advance the convenience and delivery of subcutaneous Remodulin”. Rothblatt is a collaborator on inventions with DEKA's founder Dean Kamen.

As of 2017, United Therapeutics markets five medicines with over a dozen new medicines in development. The marketed medicines are Remodulin, Tyvaso, Orenitram and Adcirca for pulmonary arterial hypertension, and Unituxin for neuroblastoma. Clinical trials of new medicines related to pulmonary hypertension include INCREASE for interstitial lung disease, SOUTHPAW for heart failure, PERFECT for COPD and SAPPHIRE for gene therapy. Other new medicines being developed include dinutuximab for Small Cell Lung Cancer, and meter dose inhaler preparations for pulmonary selective vasodilation.

United Therapeutics generally develops medicines under a pharmacogenomic paradigm that emphasizes association of clinical trial outcomes with genetic polymorphisms identified from whole genome sequencing of patients enrolled in clinical studies. The company has a goal of ultimately providing prescribing information that includes differential expectations based upon bioinformatic knowledge gained from genome sequencing.

United Therapeutics is also developing a unique type of biologic medicinal product known as a manufactured organ. This type of biologic would be transplanted into the patient as a substitute for a failing organ. The company has regenerative medicine products such as these being developed via xenotransplantation, allogenic recellularization and autologous bioprinting technologies.

According to Forbes journalist Tim Worstall, a "lucrative secondary market" emerged by 2015 in the form of vouchers that "require the FDA to shorten its decision deadline to six months from the standard 10 months—potentially giving companies an extra four months’ worth of sales. The voucher doesn’t guarantee the FDA will approve the drug." In August 2015 United Therapeutics sold the United States Food and Drug Administration voucher they were awarded in March 2015 for Unituxin, the new treatment for high-risk neuroblastoma in pediatric patients, to AbbVie for $350 million. A federal agency, the U.S. National Cancer Institute in partnership with the Children’s Oncology Group, were the initial developers of Unituxin. In 2010 United Therapeutics were under contract with NCI to "conduct late-stage clinical testing, and to manufacture and market the drug".