Ironwood Pharmaceuticals Reports First Quarter 2022 Results; Maintains Full Year 2022 Financial Guidance - LINZESS (Iinaclotide) prescription demand growth increased 11% year-over-year; LINZESS U.S.

Pharmaceuticals Reports First Quarter 2022 Results; Maintains Full Year 2022 Financial Guidance

LINZESS (Iinaclotide) prescription demand growth increased 11% year-over-year; LINZESS U.S. net sales of $232 million,

an increase of 8% year-over-year -

revenue of $98 million; U.S. LINZESS collaboration revenue of $94 million -

GAAP net income of $39 million and adjusted EBITDA of $58 million;

ended Q1 2022 with $593 million in cash and cash equivalents -

Mass., May 5, 2022 - Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a GI-focused healthcare company, today reported

its first quarter 2022 results and recent business performance.

"Continuing the growth and momentum from 2021 when LINZESS exceeded

$1 billion in U.S. net sales and earned blockbuster status, we believe we are in a strong position to realize our vision of becoming the

leading U.S. GI healthcare company," said Tom McCourt, chief executive officer of Ironwood. "We continue to be excited by

the performance of LINZESS, which has delivered another quarter of double-digit prescription demand growth year-over-year. We believe

that our focused investments and commitment to reaching new patients will continue to drive demand growth moving forward. Beyond LINZESS,

we are making progress with our ongoing clinical trials and remain on track with the previously shared data readout timing. We are also

focused on strengthening our pipeline through the in-license or acquisition of innovative GI assets, which we believe will position our

company for continued growth."

First Quarter 2022 Financial Highlights1

(in thousands, except for per share amounts)

First Quarter 2022 Corporate Highlights

First Quarter Financial Results

1 Adjusted EBITDA is calculated by subtracting mark-to-market

adjustments on derivatives related to Ironwood's 2022 Convertible Notes, restructuring expenses, net interest expense, income taxes,

depreciation and amortization from GAAP net income. For purposes of this guidance, Ironwood has assumed that it will not incur material

expenses related to business development activities in 2022.

Non-GAAP Financial Measures

Ironwood presents non-GAAP net income and non-GAAP net income per share

to exclude the impact of net gains and losses on derivatives related to Ironwood's 2022 Convertible Notes that are required to be

marked-to-market, restructuring expenses, and the release of the company's valuation allowance

against the majority of deferred tax assets in the second quarter of

2021. Non-GAAP adjustments are further detailed below:

Ironwood also presents adjusted EBITDA, a non-GAAP measure, as well

as guidance on adjusted EBITDA. Adjusted EBITDA is calculated by subtracting mark-to-market adjustments on derivatives related to Ironwood's

2022 Convertible Notes, restructuring expenses, net interest expense, income taxes, depreciation and amortization from GAAP net income.

The adjustments are made on a similar basis as described above related to non-GAAP net income, as applicable.

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. For a reconciliation of non-GAAP net income and non-GAAP net income

per share to GAAP net income and GAAP net income per share, respectively, and for a reconciliation of adjusted EBITDA to GAAP net income,

please refer to the tables at the end of this press release.

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.

Conference Call Information

Ironwood will host a conference call and webcast at 8:30 a.m. Eastern

Time on Thursday, May 5, 2022 to discuss its first quarter 2022 results and recent business activities. Individuals interested in participating

in the call should dial (888) 330-2384 (U.S. and Canada) or (240) 789-2701 (international) using conference ID number and event passcode

4671230. To access the webcast, please visit the Investors section of Ironwood's website at www.ironwoodpharma.com at least 15

minutes prior to the start of the call to ensure adequate time for any software downloads that may be required. The call will be available

for replay via telephone starting at approximately 11:30 a.m. Eastern Time on May 5, 2022 running through 11:59 p.m. Eastern Time on

May 19, 2022. To listen to the replay, dial (800) 770-2030 (U.S. and Canada) or (647) 362-9199 (international) using conference ID number

4671230. The archived webcast will be available on Ironwood's website for 14 days beginning approximately one hour after the call

About Ironwood Pharmaceuticals

Ironwood Pharmaceuticals (Nasdaq: IRWD) is a leading 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). Under the guidance of our seasoned industry leaders, we

continue to build upon our history of GI innovation and challenge what has been done before to shape what the future holds. 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,

We routinely post information that may be important to investors on

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. 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. LINZESS should be taken at least 30 minutes before the first meal of the day.

LINZESS is contraindicated in

pediatric patients less than 2 years of age. In neonatal mice, linaclotide increased fluid secretion as a consequence of age-dependent

elevated GC-C agonism resulting in mortality within the first 24 hours due to dehydration. There was no age-dependent trend in GC-C intestinal

expression in a clinical study of children 2 to less than 18 years of age; however, there are insufficient data available on GC-C

intestinal expression in children less than 2 years of age to assess the risk of developing diarrhea and its potentially serious consequences

in these patients. The safety and effectiveness of LINZESS in patients less than 18 years of age have not been established.

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 in adults for the treatment of both

irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC).

IMPORTANT SAFETY INFORMATION

Warnings and Precautions

Common Adverse Reactions (incidence 2% and greater than

Please see full Prescribing Information including Boxed Warning: http://www.allergan.com/assets/pdf/linzess_pi