Ironwood Pharmaceuticals Maintains FY 2023 Financial Guidance and Announces FY 2024 Financial Guidance - Expects high-single digit percentage LINZESS EUTRx prescription demand growth in 2024 - - Exp

Ironwood Pharmaceuticals

Maintains FY 2023 Financial Guidance and Announces FY 2024 Financial Guidance

high-single digit percentage LINZESS EUTRx prescription demand growth in 2024 -

2024 adjusted EBITDA of greater than $150 million -

BOSTON, Mass., January 8, 2024 - Ironwood Pharmaceuticals, Inc.

(Nasdaq: IRWD), a GI-focused healthcare company, today announced financial guidance for full year 2024. The results were announced in

advance of the Company's presentation at the 42nd Annual J.P. Morgan Healthcare Conference, which will take place on

Wednesday, January 10, 2024 at 11:15 a.m. PT / 2:15 p.m. ET.

"We believe the significant progress we made across our strategic

priorities last year has strengthened our position to be the leading GI healthcare company," said Tom McCourt, chief executive

officer of Ironwood. "We are on track to deliver on our 2023 LINZESS U.S. net sales guidance, driven by continued strong prescription

demand and remain encouraged about the future growth potential of the brand. Furthermore in 2023, we strengthened our GI pipeline with

the addition of apraglutide, which we believe has blockbuster potential in short bowel syndrome requiring parenteral support, if approved."

"Looking ahead in 2024, we remain committed to maximizing LINZESS,

advancing our GI development pipeline and delivering profits and cash flows. We expect to deliver another year of high-single digit percentage

LINZESS demand growth and maintain class-leading formulary access, which we believe will result in low-single digit percentage LINZESS

U.S. net sales growth in 2024. In addition, we expect to deliver greater than $150 million in adjusted EBITDA in 2024. We are looking

forward to an exciting and potentially transformational year for Ironwood with several catalysts ahead of us, highlighted by the topline

data from our STARS Phase 3 study expected in March in SBS-IF and topline data from the ongoing Phase 2 study for CNP-104 expected

in the third quarter. We believe the advancement of our pipeline programs, combined with continued strong LINZESS demand growth, uniquely

position our company for success in our mission to be the leader in GI."

Full Year 2023 Financial Guidance and Full Year 2024 Financial

Ironwood is maintaining its previous FY

2023 financial guidance and is providing FY 2024 financial guidance.

J.P. Morgan Healthcare Conference Presentation

As previously announced, Ironwood

will present a corporate overview at the 42nd Annual J.P. Morgan Healthcare Conference on Wednesday, January 10, 2024

at 11:15 a.m. PT / 2:15 p.m. ET. A live audio webcast of Ironwood's presentation is accessible through the Investors

section of the Company's website at www.ironwoodpharma.com. To access the webcast, please log on to the Ironwood website

approximately 15 minutes prior to the start time to ensure adequate time for any software downloads that may be required. A replay of

the webcast will be available on Ironwood's website after the event has completed.

EBITDA is calculated by subtracting mark-to-market adjustments on derivatives related to our 2022 Convertible Notes, restructuring expenses,

net interest expense, income taxes, depreciation and amortization, and acquisition-related costs from GAAP net income. For purposes of

the 2024 guidance, we have assumed that Ironwood will not incur material expenses related to business development activities in 2024. Ironwood

does not provide guidance on GAAP net income or a reconciliation of expected adjusted EBITDA to expected GAAP net income because,

without unreasonable efforts, it is unable to predict with reasonable certainty the non-GAAP adjustments used to calculate adjusted

EBITDA. These adjustments are uncertain, depend on various factors and could have a material impact on GAAP net income for the guidance

period. Management believes this non-GAAP information is useful for investors, taken in conjunction with Ironwood's GAAP financial

statements, because it provides greater transparency and period-over-period comparability with respect to Ironwood's operating

performance. These measures are also used by management to assess the performance of the business. Investors should consider these non-GAAP

measures only as a supplement to, not as a substitute for or as superior to, measures of financial performance prepared in accordance

with GAAP. In addition, these non-GAAP financial measures are unlikely to be comparable with non-GAAP information provided by other companies.

Full year 2023 adjusted EBITDA guidance reflects a one-time charge of approximately $1.1 billion related to acquired in-process research

and development from the acquisition of VectivBio in the second quarter of 2023. Full year 2024 adjusted EBITDA guidance also excludes

any costs associated with a potential CNP-104 option exercise.

About Ironwood Pharmaceuticals

Ironwood Pharmaceuticals (Nasdaq: IRWD), an S&P SmallCap 600

company, is a leading global gastrointestinal (GI) healthcare company on a mission to advance the treatment of GI diseases and redefine

the standard of care for GI patients. We are pioneers in the development of LINZESS (linaclotide), the U.S. branded prescription

market leader for adults with irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC). LINZESS is

also approved for the treatment of functional constipation in pediatric patients ages 6-17 years-old. Ironwood is also advancing apraglutide,

a next-generation, long-acting synthetic GLP-2 analog being developed for rare gastrointestinal diseases, including short bowel syndrome

with intestinal failure (SBS-IF) as well as several earlier stage assets. Building upon our history of GI innovation, we keep patients

at the heart of our R&D and commercialization efforts to reduce the burden of GI diseases and address significant unmet needs.

Founded in 1998, Ironwood Pharmaceuticals

is headquartered in Boston, Massachusetts, and has additional operations in Basel, Switzerland.

post information that may be important to investors on our website at www.ironwoodpharma.com.

About LINZESS (Linaclotide)

LINZESS is the #1 prescribed brand in the U.S. for the treatment

of adult patients with irritable bowel syndrome with constipation ("IBS-C") or chronic idiopathic constipation ("CIC"),

based on IQVIA data.

LINZESS is a once-daily capsule that helps relieve the abdominal pain,

constipation, and overall abdominal symptoms of bloating, discomfort and pain associated with IBS-C, as well as the constipation, infrequent

stools, hard stools, straining, and incomplete evacuation associated with CIC. LINZESS relieves constipation in children and adolescents

aged 6 to 17 years with functional constipation. The recommended dose is 290 mcg for IBS-C patients and 145 mcg for CIC patients, with

a 72 mcg dose approved for use in CIC depending on individual patient presentation or tolerability. In children with functional constipation

aged 6 to 17 years, the recommended dose is 72 mcg.

LINZESS is not a laxative; it is the first medicine approved by the

FDA in a class called GC-C agonists. LINZESS contains a peptide called linaclotide that activates the GC-C receptor in the intestine.

Activation of GC-C is thought to result in increased intestinal fluid secretion and accelerated transit and a decrease in the activity

of pain-sensing nerves in the intestine. The clinical relevance of the effect on pain fibers, which is based on nonclinical studies,

has not been established.

In the United States, Ironwood and AbbVie co-develop and co-commercialize

LINZESS for the treatment of adults with IBS-C or CIC. In Europe, AbbVie markets linaclotide under the brand name CONSTELLA for

the treatment of adults with moderate to severe IBS-C. In Japan, Ironwood's partner, Astellas, markets linaclotide under the brand

name LINZESS for the treatment of adults with IBS-C or CIC. Ironwood also has partnered with AstraZeneca for development and commercialization

of LINZESS in China, and with AbbVie for development and commercialization of linaclotide in all other territories worldwide.

LINZESS Important Safety Information

INDICATIONS AND USAGE

LINZESS (linaclotide) is indicated for the treatment of both

irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) in adults and functional constipation (FC)

in children and adolescents 6 to 17 years of age. It is not known if LINZESS is safe and effective in children with FC less than 6 years

of age or in children with IBS-C less than 18 years of age.

IMPORTANT SAFETY INFORMATION

Warnings and Precautions

Common Adverse Reactions (incidence 2% and greater than

Please see full Prescribing Information including Boxed Warning:

LINZESS and CONSTELLA are registered trademarks of Ironwood

Pharmaceuticals, Inc. Any other trademarks referred to in this press release are the property of their respective owners. All rights

Forward-Looking Statements

This press release contains forward-looking statements. Investors

are cautioned not to place undue reliance on these forward-looking statements, including statements about Ironwood's ability to

execute on its mission; Ironwood's strategy, business, financial position and operations; Ironwood's ability to drive growth

and profitability; the demand, development, commercial availability and commercial potential of linaclotide, including unlocking new

opportunities and maintaining class-leading formulary access for LINZESS, and the drivers, timing, impact and results thereof; the potential

indications for, and benefits of, linaclotide; our financial performance and results, and guidance and expectations related thereto;

LINZESS prescription demand growth, LINZESS U.S. net sales growth, total revenue and adjusted EBITDA in 2023 and 2024; the commercial