Somaxon Pharmaceuticals, Inc.

June 10, 2010

Jefferies Global Life Sciences ConferenceNasdaq: SOMX

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Forward Looking StatementsThis presentation contains forward-looking statements about our business, including our commercialization timeline and plans, potential partnerships or other strategic collaborations, future financial results and events that have not yet occurred. Operating in the pharmaceutical industry inherently involves significant risks and uncertainties, including the risks outlined under “Risk Factors” and elsewhere in our Annual Report on Form 10-K and our other filings made with the SEC from time to time. Our actual results may differ materially from our expectations due to these risks and uncertainties, including our near-term dependence on the success of our lead product candidate, Silenor®, and factors relating to ability to raise sufficient capital, ability to attract a strategic partner, competition, intellectual property protection, industry environment, and other matters. Somaxon undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof.

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Somaxon Business StrategyDevelop and Commercialize Highly Differentiated Products– Target late-stage or currently marketed assets

– Address unmet medical need and patient dissatisfaction

– Maximize value of Silenor

Deploy a U.S. Commercial Organization – Focus on the CNS therapeutic area

– Cover high-prescribing physicians with a targeted sales force

– Create efficiencies through strategic outsourcing

Establish Commercial Collaborations– Effectively leverage partner resources

– Reach broader prescriber universe

– Consider licensing, co-promotion or M&A to accelerate growth

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Highlights

FDA approved Silenor for the treatment of insomnia characterized by sleep maintenance difficulty, March 17, 2010

Raised $53MM in secondary offering in March 2010

U.S. commercial collaboration discussions ongoing

Somaxon’s commercial build-out underway

Silenor launch in 2H 2010

Pursuing ex-U.S. Silenor licensing partner(s)

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Silenor for InsomniaNear-term Opportunity

– Target launch 2H 2010 – Favorable market dynamics commercial upside– Launch Ready campaign – Product profile supports potential for meaningful share of the market

Silenor – A Highly Differentiated Product for Insomnia

– Differentiated Mechanism of Action• H1 affinity vs. GABA or melatonin

– Strong Clinical Efficacy Profile• Primary efficacy endpoint achieved statistical significance in all four Phase 3

studies• Sleep maintenance ≥ 7 hours

– Favorable Safety and Tolerability Profile• Not scheduled • Adverse events comparable to placebo• No GABA-ergic related side effects

A Restless Market

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Large and Accessible MarketOver 67 million TRx’s and > $2 billion in sales in the U.S. 2009

U.S Market remains under-diagnosed and under-treated– 70 million estimated to suffer from insomnia

– 14 million (20%) are currently on Rx treatment

– 56 million utilize OTC/not on Rx treatment

Concentrated market: ~44,000 doctors write half the TRx’s– 30% of highest prescribing doctors are specialists

• Top decile prescribers average >1000 Rx’s /year

Opportunity to accelerate prescription growth with the introduction of a novel and differentiated product– 70% of patients would ask for Silenor on the next doctor visit

– 12% of patients stated they would make a special visit to ask for SilenorSources: IMS Health data, Roth et al, 1999, Somaxon Market Research_2008 (Insomnia Treatment: The Consumer Perspective N=1,764)

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Sleep Maintenance is Primary Issue

65%

35%

Sleep Problem in Past Month At Least a Few Nights/Week

49%Woke Unrefreshed

42%Frequent Nocturnal

Awakenings

29%Early Morning Awakenings

26%Difficulty Falling Asleep

National Sleep Foundation.Summary of findings: 2008 Sleep in America poll. n = 1760 respondents

Any Sleep ProblemRarely, Never, Don’t know

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Insomnia MarketCurrent options force patients and physicians to compromise– GABA-ergic drugs provide varying degrees of efficacy but

involve compromise on tolerability and risk of addiction– OTCs address addiction concerns but involve compromise

on efficacy and tolerability– Melatonin-receptor agonists address addiction and

tolerability concerns but involve compromise on efficacy

Only 25% of patients “Very Satisfied” with current insomnia prescription and 40% claim they switched medications in the last year.

Source: Somaxon Market Research_2008 (Insomnia Treatment: The Consumer Perspective N=1,764)

A Novel Treatment for Insomnia

Silenor

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Starting With a DifferentiatedMechanism of Action

Histamine (H1) is one of several waking neuro-transmitters important in the arousal system

Silenor has high affinity for H1 receptors– Twenty-fold more potent than diphenhydramine, and significantly more

selective

Silenor has significant effects at night through the blockade of H1, which promotes and maintains sleep

Specific H1 blockade does not prevent or diminish arousal due to other neurotransmitters in the arousal system

Sources: Mansbach, ECMP 2008 Poster Presentation

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3 mg6 mg

Sleep Efficiency Throughout the Night

DXP 3 mg

PBO

DXP 6 mg

Hour of the Night

Sle

ep

Eff

icie

ncy

Source: Somaxon Phase 3 Clinical Study Results (Study SP-0501 Adult Chronic 35 day)

50%

55%

60%

65%

70%

75%

80%

85%

90%

95%

1 2 3 4 5 6 7 80.39160.0492

<0.0001<0.0001

0.00140.0001

0.00020.0006

0.06500.0020

0.06930.0282

0.0063<0.0001

0.06710.1040

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Incidence (%) of Treatment-Emergent Adverse Reactions in Long-term Placebo-Controlled Clinical Trials

System Organ ClassPreferred Term*

Placebo(N=278)

Silenor3 mg

(N=157)

Silenor6 mg

(N=203)Nervous System Disorders

Somnolence/Sedation 4 6 9Infections and Infestations

Upper Respiratory Tract Infection/Nasopharyngitis

2 4 2

Gastroenteritis 0 2 0Gastrointestinal Disorders

Nausea 1 2 2Vascular Disorders

Hypertension 0 3 <1* Includes reactions that occurred at a rate of ≥ 2% in any Silenor-treated group and at a higher rate than placebo.

Source: Silenor® Package Insert_March 2010

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Silenor: Just What the Patient OrderedTreat sleep maintenance insomnia

– The most significant insomnia complaint– 7-8 hours of sleep with Silenor

Prevention of early morning awakenings – a full night’s sleep– Unique potential positioning for Silenor

Attractive safety profile– NO clinically meaningful evidence of next-day residual effects– NOT DEA scheduled– NO abuse potential – NO risk of dependency– NO withdrawal symptoms– NO tolerance with long term use– NO complex sleep behaviors observed– NO amnesia, hallucinations or other GABA-related side effects– NO disruption of sleep stages

Silenor Commercialization

Silenor

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Changing Market Dynamics Create Opportunities

Solid “window of opportunity” for new treatments– A void of new and differentiated insomnia treatments since 2006

– No “novel” compounds expected to launch in near term • Clinical and regulatory setbacks for several drugs in development

• Somaxon estimates several years before new competition comes to market

Number of primary details is decreasing – Recent sales force reductions

– Competitive brands lack differentiated message

Competitive promotional spending is decreasing– DTC spending down dramatically year-over-year

– Consistent trend across brands

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“Plan to Win”Capitalize on the Changing Market Dynamics– Competitor “turbulence”– Lack of differentiated insomnia treatments– Shift from expensive DTC strategy

Pre-launch - Raise Awareness– Web based initiatives– Publications– Professional meetings (e.g. APSS)

Launch with a Competitive Sales Force– Target high value physicians– Utilize non-personal promotional efforts to leverage into lower deciles– Exploit Silenor sampling advantage

Integrated Professional Campaign Developed– Strong branding elements– Patient Education Programs– Technology driven physician education

Targeted Consumer Campaign Developed– “Direct to Insomniac” communication via Web– Point of Care Programs/Public Relations

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Silenor BrandingBrand Identity

– Refreshingly Different

Key Messages– A full 7-8 hours of sleep– Safe for chronic use– Non-addicting, no abuse potential– Placebo-like side effect profile– No meaningful hangover effect– Unique MOA

Positioning-Silenor is first-line therapy

for sleep maintenance insomnia

Broad clinical profileSafety

TolerabilityPatient benefits

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Professional CampaignIntegrated marketing campaign to reach High Value Physicians (HVP) with both personal and non-personal promotional efforts– Messaging Finalized

• Supportive sales aids and branded marketing materials– Brand Awareness programs– Leverage on-line/media

Packaging designed to reinforce Brand imagery and product features– Reliance on dose pack but bottles available– Sample and trade packaging identical and distinctive

Samples – a competitive advantage– Drives physician access– 4 count sample packs for sales rep delivery and direct distribution

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Silenor Branding

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Patient Starter Kit

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Patient Brochure / Co-Pay Card

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Silenor Dose Pack

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Direct to Consumer CampaignWeb and Point of Care outreach “Direct to Insomniac”

Web property deployment– www.silenor.com– Search engine optimization– User database

Outreach through Web MD– Directed approach – Most trusted and searched website for medical inquiries

Public Relations – Media outreach at launch

Point of Care – Pharmacy– Direct product messaging to OTC sleep aid and anti-depressant users

Point of Care – MD Office– In-office video and print materials

• Rep and direct distributed

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Silenor.com

Somaxon Pharmaceuticals, Inc.

Corporate Summary

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Commercial Collaboration for Silenor

GOALSSuccessful Silenor launch in 2H 2010Build a focused Somaxon commercial organizationMaximize shareholder value

Traditionallicensing

withco-promotion

rights

Co-promotionwith shared

revenues and costs

M&A to gain access to

sales infrastructure/

products

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Financials

Cash, cash equivalents& marketable securities (3/31/10)

Shares outstanding

Fully diluted shares

$58.5 MM

34.3 MM

42.7 MM

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Somaxon Value PropositionSilenor – Highly differentiated insomnia treatment

– Favorable market dynamics

– “Launch ready” campaign

– Attractive market potential

Experienced management team – Significant commercial transaction and product launch experience

2010 milestones– Potential Silenor commercial collaboration(s)

– Deploying a specialty commercial operation

– 2H 2010 Silenor launch in US

Somaxon Pharmaceuticals, Inc.