Ironwood Pharmaceuticals Provides Update on FY 2021 Financial Guidance and Announces FY 2022 Financial Guidance - LINZESS Expected to Achieve Blockbuster Status with U.S. Net Sales in Excess of $1 B

Ironwood Pharmaceuticals Provides Update on

FY 2021 Financial Guidance and Announces FY 2022 Financial Guidance

LINZESS Expected to Achieve Blockbuster Status with U.S. Net Sales in Excess of $1 Billion in 2021 -

- Initiates Board Authorized

Share Repurchase Program in Q4 2021 -

Continued Double-Digit LINZESS Prescription Demand Growth in 2022 -

BOSTON, Mass., January 10, 2022

- Ironwood Pharmaceuticals, Inc. (Nasdaq: IRWD), a GI-focused healthcare company, today provided

updated financial guidance for full year 2021 and announced financial guidance for full year 2022. The results were announced in advance

of the Company's presentation at the 40th Annual J.P. Morgan Healthcare Conference, which will take place on Wednesday, January 12,

2022 at 7:30 a.m. ET.

"Among the key highlights of 2021 was the progress we made across

our three strategic priorities which strengthened our organization and delivered strong operational performance," said Tom McCourt,

chief executive officer of Ironwood. "We expect to report solid financial results in 2021 and deliver our third consecutive year

of profits. Notably, we expect LINZESS to exceed $1 billion in U.S. net sales reaching blockbuster status, a significant accomplishment

for Ironwood. Additional highlights include advanced innovation through our expanded pipeline and development programs, and the initiation

of a share repurchase program of up to $150 million through December 2022."

"Looking ahead in 2022, we remain committed to further advancing

our strategic priorities, unlocking new opportunities for LINZESS and strengthening our pipeline with innovative GI assets. We expect

continued double-digit LINZESS prescription demand growth, further reinforcing its position as the #1 prescribed brand in the U.S. for

the treatment of adults with IBS-C or chronic idiopathic constipation. For 2022, we have also refined our mix of brand investment and

class-leading payer access, which we expect to result in low single digit LINZESS net sales growth, and we expect to deliver strong brand

margins. At the same time, we expect adjusted EBITDA growth well in excess of Ironwood revenue growth in 2022. Overall, we believe we

remain well positioned for long term growth and are focused on delivering patient benefit and shareholder value."

Updated Full Year 2021 Financial Guidance1

LINZESS U.S. net sales to exceed $1 billion in 20212, with LINZESS U.S. net sales growth, total Ironwood revenues,

and Ironwood adjusted EBITDA to be at the high end of our previously disclosed guidance ranges for full year 2021. The table below summarizes

Ironwood's revised full year 2021 guidance.

Ironwood now expects:

Update on Board Authorized Share Repurchase

Ironwood repurchased $27 million of shares

of the Company's common stock in the fourth quarter of 2021 under its board authorized share repurchase program of up to $150 million

through December 31, 2022.

Full Year 2022 Financial Guidance

For full year 2022, Ironwood expects

LINZESS U.S. net sales growth to be in the low single digits, total revenues to be between $420 million and $430 million and adjusted

EBITDA3 to be greater than $250 million. The table below summarizes Ironwood's full year 2022 guidance outlined above.

unaudited, preliminary and estimated amounts and may change as we receive final 2021 data and complete the preparation of our 2021 financial

net sales is unaudited, preliminary and based on estimates, and may change as we receive final 2021 data from AbbVie Inc. and as we and

AbbVie complete the preparation of our respective 2021 financial statements. LINZESS U.S. net sales are reported by AbbVie and LINZESS

costs incurred by each of us and AbbVie are reported in our respective financial statements.

3 Adjusted 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, from GAAP net income. For purposes of this guidance, we have assumed that

Ironwood will not incur material expenses related to business development activities in 2022. 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.

In 2022, Ironwood expects:

J.P. Morgan Healthcare Conference Presentation

announced, Ironwood will present a corporate overview at the 40th Annual J.P. Morgan Healthcare Conference on Wednesday, January 12,

2022 at 7:30 a.m. ET. The event is being held virtually and 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 for 14 days following the conference.

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, Massachusetts.

We routinely post information that may

Twitter and on LinkedIn.

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