Why direct-to-consumer ad spend stopped predicting where the AI engines land, and what pharmaceutical companies should do about it.

The U.S. pharmaceutical industry spent an estimated $8 billion on direct-to-consumer advertising in 2024, the largest DTC ad category in America, larger than auto or financial services. The ads run during network news, sports, and prestige drama, built to put a drug name in front of a patient so the patient asks the doctor about it.

Edited on June 19, 2026.

The campaign worked for thirty years. It is working less now.

New 5W research measured how AI answer engines, including ChatGPT, Claude, Perplexity, Gemini, and Google AI Overviews, describe and rank the 25 largest pharmaceutical companies. 5W ran more than sixty patient and consumer prompts, five times per engine, in clean sessions. The finding: ad spend does not predict citation share. What patients self-research does.

Which pharma companies lead AI engine citation share?

Eli Lilly leads the citation surface at an estimated 12.5% share, with Novo Nordisk at 11.5%. Together, the two companies hold roughly a quarter of all corporate citations across the pharmaceutical category. Their drugs, including Ozempic, Wegovy, Mounjaro, and Zepbound, generated roughly $70 billion in combined 2025 sales and became cultural events, showing up in late-night monologues, major newspaper features, and Wikipedia entries that AI engines retrieve.

By contrast, Merck makes Keytruda, the best-selling prescription drug in the world, yet ranks fifth in citations according to the study. Oncology drugs are prescribed by oncologists, and patients do not type Keytruda into a chatbot the way they type Ozempic. Revenue and AI citation share are different scoreboards.

Why is AbbVie a useful test case?

AbbVie has been among the largest direct-to-consumer advertisers in U.S. healthcare for a decade, running heavy national TV and digital schedules for Humira, Skyrizi, and Rinvoq. AbbVie ranks sixth in citation share at an estimated 5.0%, below Pfizer, which benefits from residual recognition tied to its COVID-19 vaccine, and below Johnson & Johnson, which carries diversified-conglomerate weight.

This is not an indictment of DTC advertising; it is a measurement of where the channel stops compounding. A TV spot makes a drug name familiar. Familiarity alone does not produce a retrievable record. What produces the record is editorial coverage, trial data, the Wikipedia entry, the analyst note, the pharmacist explainer on a site like Drugs.com, and coverage from outlets such as STAT or Reuters. The spot can seed all of that; it does not substitute for it.

What is actually happening when patients research drugs in AI systems?

A growing share of U.S. consumers now begin product research inside an AI system rather than a traditional search engine, and in healthcare that share appears to be rising quickly. Patients ask what the difference is between Ozempic and Mounjaro, which works better for sleep apnea, or whether insurance is likely to cover a given drug. The engine returns a paragraph that names companies; in the prompts 5W tested, Lilly and Novo appeared by name in roughly a quarter of all pharma answers.

By the time many patients reach the doctor, part of the brand conversation has often already happened in the chatbox, ahead of the appointment itself.

What should pharma communications teams do about this?

  • Audit corporate citation share on a regular schedule; trial readouts, pricing news, and patent events can move the picture faster than the budget cycle.
  • Connect the drug brand to the company name in every retrievable surface. If the public record says "the maker of Ozempic" without naming Novo Nordisk, citation share is being left on the table.
  • Earn the business and health editorial record. Outlets such as Reuters, Bloomberg, STAT, and Fierce Pharma feed pharma citations disproportionately.
  • Keep the reference layer accurate. Company filings, Wikipedia, and drug-reference sites are heavily retrieved, and errors there tend to propagate.
  • Treat trial readouts and approvals as citation events; a peer-reviewed medical journal paper can function as a citation source for years.
  • Engage pricing and access coverage directly, since AI answers often surface pricing context inside corporate queries.
  • Treat DTC TV spend as one channel among several, not a citation strategy on its own.

What is the bigger picture for pharma marketing?

Pharma built decades of brand awareness on television, and the industry is still buying that channel at scale, even as the buyer's research behavior has shifted toward AI systems for the questions that used to open in the exam room.

Eli Lilly and Novo Nordisk built drugs people talk about, and the editorial and reference record around those drugs followed. Merck makes the best-selling drug on earth and ranks fifth in the study's answer set. Closing that kind of gap is a communications discipline; 5W calls it AI Communications. AbbVie, Pfizer, Bristol Myers Squibb, and other heavy DTC spenders have a choice about whether they fund the channel or the underlying infrastructure.

The full Pharma / Rx AI Visibility Index 2026 is available at 5wpr.com, with no paywall, PDF, or email gate.

Important framing: this index measures AI citation share for corporate communications and marketing strategy purposes only. It is not medical advice. Medication decisions must be made with a qualified physician or pharmacist.

FAQ

Why doesn't pharmaceutical ad spend predict AI engine citation share?
A TV spot makes a drug name familiar, but familiarity alone does not produce a retrievable record. That record comes from editorial coverage, trial data, Wikipedia entries, analyst notes, pharmacist explainers, regulatory filings, and earnings coverage.

Which pharmaceutical companies lead AI engine citation share, and why?
Eli Lilly leads at an estimated 12.5% share and Novo Nordisk at 11.5%, together holding roughly a quarter of all corporate citations in the category, largely because their drugs became cultural events generating a large editorial and reference record.

How has patient research behavior changed?
A growing share of U.S. consumers now begin product research with an AI system rather than a search engine, and that share appears to be rising quickly in healthcare specifically.

What is the single most important action a pharma communications team can take?
Connect the drug brand to the company name in every retrievable surface, then earn the business and health editorial record, since outlets such as Reuters, Bloomberg, STAT, and Fierce Pharma feed pharma citations disproportionately.

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Ronn Torossian is the founder and chairman of 5W AI Communications, the AI Communications Firm. He is the publisher of Everything-PR and the author of two best-selling editions of For Immediate Release. He has contributed to Forbes, CNN, and CNBC, and lectures on crisis PR at Harvard Business School.