Merck (MRK): Revenue Up 5%, But $550M Of Purchase Timing Was About Two-Thirds Of The Increase

Investment Thesis

Merck reported third-quarter revenue of $18.1B, up 5%, but the CFO also said purchase timing added about $550M to U.S. sales in the quarter, and that part of it will unwind in the fourth quarter and 2027. Without that benefit, revenue growth was roughly 2% (d). Keytruda is still about 47% of revenue, operating expenses grew 12%, and the full-year EPS guide leaves little room for the other quarters.

• Revenue. Total revenue was $18.1B, up 5% (4% excluding FX). The Keytruda family, including Keytruda QLEX, was $8.6B, up 6%.
• Purchase timing. About $550M of U.S. purchases benefited Q3: $200M for Keytruda, $50M for Winrevair and $300M for vaccines. Keytruda's $200M and Winrevair's $50M unwind in Q4. Of the vaccine amount, $50M unwinds in Q4 and $250M in 2027.
• Underlying growth. The $550M equals about 64% of the roughly $0.86B revenue increase (d), leaving growth of about 1.8% (d). For Keytruda, $200M is about 41% of its increase, leaving about 3.5% (d).
• Growth products. Winrevair was $694M (+94%), Welireg $370M (+58%), Gardasil $2.0B (+14%), and Ohtuvayre $184M. Animal health rose 3%.
• Costs. Non-GAAP operating expenses rose 12% to $7.4B, more than twice revenue growth. Non-GAAP gross margin fell slightly to 81.4%. A $400M upfront business development charge compares with $300M a year earlier.
• EPS. Non-GAAP EPS was $2.49, including a $0.12 per share charge for the license deal. The full-year guide is $2.77 to $2.82, so the other three quarters together would earn about $0.31 (d).
• Guidance. 2026 revenue is guided to $66.8B to $67.3B (+3% to 4%), gross margin about 81%, operating expenses $42.4B to $42.9B, tax rate 32% to 33%, buybacks about $3B.
• This article contains no price target or rating. Every figure comes from the executives' spoken remarks on the Q3 call or a named source, and anything I calculated is marked (d).

Bottom line. Merck's Q3 looks like steady 5% growth, but the quality is lower than the headline: roughly two-thirds came from purchase timing that management says will unwind. Underlying growth of about 2%, a Keytruda franchise at 47% of revenue and operating expenses growing 12% mean the investor case depends on Winrevair, Welireg and the 2027 expense outlook.

Source: Merck Q3 2026 earnings call transcript, Motley Fool, Oct 29, 2026.

Q3 2026 At A Glance

Source: Merck Q3 2026 call transcript.

What The Market Believes vs. What The Data Actually Shows

The call gave no consensus; prices are in the Valuation Snapshot.

A 5% growth rate would normally support the premium valuation of a large-cap pharmaceutical. The timing adjustment matters because Merck's own call quantified it, which gives investors a rare chance to separate reported from underlying growth.

Forensic #1: $550M Of Purchase Timing Was Most Of The Increase

Merck Q3 2026 Revenue Growth With And Without U.S. Purchase Timing, Derived (Self-Made)

Of the $550M, about $300M is expected to unwind in Q4 ($200M Keytruda, $50M Winrevair, $50M vaccines) and $250M of vaccine purchases in 2027 (d). A CDC purchase of about $250M in 2026 also unwinds in 2027.

Why it matters. About $300M gives back in Q4, so reported growth next quarter will look weaker, and the vaccine amount reverses again in 2027 along with a CDC purchase of about $250M. An investor modelling 2027 should treat these as a headwind on a high base, not as underlying demand.

Source: Merck Q3 2026 call transcript. Derived values use rounded growth rates and are approximate.

Forensic #2: Keytruda Is 47% Of Revenue

Merck Q3 2026 Revenue By Product, $B (Self-Made)

Winrevair grew 94% but is under 4% of revenue. About 1.6 thousand new U.S. patients started on it, and about 30% were not on a prostacyclin. Welireg's growth is spoken as 58% at $370M; the page summary lists $307M, which I treat as a transcription difference.

Why it matters. Keytruda is the main swing factor, and its growth excluding timing, about 3.5% (d), is slower than the company total. The fast growers are small: Winrevair, Welireg, Ohtuvayre and Winflonzia together are about $1.4B, or 8% of revenue (d). Their dollar growth needs to be several times larger before it offsets any slowdown in Keytruda.

Source: Merck Q3 2026 call transcript.

Forensic #3: Operating Expenses Outgrew Revenue And A Licence Charge Hit EPS

Merck Q3 2026 Growth By Product And Operating Expenses (Self-Made)

The transcript names the licence agreement inconsistently (it renders the partner as "Ceybrion", and other sources call it "SciBrunch"), so I do not name it. The 10.9% Q3 tax rate contrasts with the 32% to 33% full-year guide, a gap the spoken remarks do not explain.

Why it matters. When operating expenses grow 12% on 5% revenue growth, margins fall unless gross margin rises, and gross margin slipped to 81.4%. Business development charges of $400M this year and $300M last year suggest that licence deals are a regular cost of keeping the pipeline full, so investors should not treat them as pure one-offs.

Source: Merck Q3 2026 call transcript.

Forensic #4: The Full-Year EPS Guide Leaves About $0.31 For Three Quarters

I did not read Merck's first- and second-quarter results, so I cannot say what large charges sit in them or in Q4. The arithmetic means either the other quarters carried charges, or Q4 will, and a reader should check the filing before drawing a conclusion.

Why it matters. A full-year guide of $2.77 to $2.82 sits well below four times Q3 EPS of $2.49, so quarters outside Q3 carry charges, and the guide is a poor basis for a P/E. The investor's task is to find EPS excluding charges, which the call did not provide, before using a multiple.

Source: Merck Q3 2026 call transcript.

Valuation Snapshot

TradingView shows Merck at $149.52, up 2.2% on the day and 41.7% year to date, about 4.7% below its Aug 25, 2026 high of $156.92. Market cap is about $368.9B. The page lists Q3 EPS of $2.49 against an estimate of $2.09, with no source or date for the estimate.

The two P/E figures differ by a factor of more than three because the full-year guide includes large charges and Q3 did not. The price is near its high while underlying revenue growth, excluding purchase timing, was about 1.8% (d), so the market is looking past the quarter.

What has to be true. Near its August high and about 42% up year to date, the stock prices in more than the roughly 2% underlying growth of Q3. The support is the 2.3% dividend yield and the growth of Winrevair and Welireg. The pressure is Keytruda concentration and the 2027 unwind.

Risks: What Would Break The Thesis

• Timing unwinds. About $300M reverses in Q4 and $250M in 2027 (d).
• Keytruda concentration. 47% of revenue in one franchise.
• Costs. Operating expenses grew 12%; 2027 underlying growth is guided to mid-to-high single digits.
• Vaccines. Capvaxive U.S. sales fell 13%.
• Data limits. The transcript is machine-generated and the release was not read.

Most of the risks are known and dated: the Q4 unwind, the 2027 unwind and expense growth. The unknown risk is how fast new products replace Keytruda.

What To Watch Next

• Q4 revenue with about $300M of timing unwinding.
• Keytruda growth excluding timing against 3.5% (d).
• Winrevair against $694M.
• The EPS bridge from $2.49 to the full-year guide.
• 2027 operating expense growth.