Questions pharmacists ask about Sig.

Sig is a clinical drug reference app for pharmacists on iPhone and iPad. Sig holds 15,497 guideline recommendations, 434 decision trees, more than 1,000 calculators, and dose rules for 405 drugs. Every result names the document and section behind the answer, and Sig works offline with no account.

Sig is written by a Doctor of Pharmacy and published by HARRIS CLINICAL SOFTWARE LLC, an Arkansas company. Sig is built for pharmacists, pharmacy technicians, students, and residents in the United States, not for patients.

Our data show that 51% of the 384 guidelines in Sig were published in 2023 or later, including 76 from 2026. Additionally, bundled content needs no network connection.

For example, a pharmacist checking gabapentin for a 78-year-old man weighing 62 kg with a serum creatinine of 2.2 mg/dL enters the values once. Sig calculates a Cockcroft-Gault creatinine clearance (Cockcroft 1976) of 24 mL/min and returns approximately 200 to 700 mg once daily, citing the Dosage and Administration section of the FDA label.

Sig is a reference that shows its work. Every dose, score, and recommendation in Sig carries the source guideline, FDA label, or table, with a section, page, or table locator. A pharmacist working with Sig can check the source instead of trusting a summary. Sig also runs offline, needs no account, and sends no analytics.

New content is drafted from a verbatim quote of 25 words or fewer, and a machine check rejects any quote not found word for word in the source. For example, where a source needs a number and prints none, Sig says Information Gap Detected rather than borrowing a number from another document.

Our data show that 100% of the 15,497 recommendations name the source section, and 34% also give a page number, as of November 3, 2026.

Additionally, Sig does not license a commercial database. The Drug Interactions tool reads current FDA labeling, assigns no severity ratings, and says so in the app.

Sig is a reference with 384 guidelines and labels holding 15,497 recommendations across 15 specialties. Sig also has 142 conditions, 434 decision trees, more than 1,000 calculators in 30 categories, and 559 curated monographs. Dose Adjustment holds 3,609 rules for 405 drugs. All of the content is stored on the device.

Our data show that 51% of the guidelines were published in 2023 or later, as of November 3, 2026.

First, infectious diseases. Antibiotic selection covers 72 syndromes and 121 organisms, with 1,647 susceptibility breakpoints and 88 expert rules.

Second, pharmacy reference. Pharmacists using Sig get the FDA Orange Book and Purple Book, controlled-substance schedules for all 50 states, and a DEA number check. Pill identification covers 19,925 products, and crush, chew, and split statements cover 643 drugs.

Third, dosing and safety, for example opioid MME, steroid equivalence, tapers, and levothyroxine and warfarin dosing. Sig adds 235 lab analytes, 3,447 counseling points, USP compounding chapters, 310 OTC ingredients, and 3 immunization schedules. Smoking cessation, religious considerations, patient assistance programs, day supply, a Sig Translator, and a live FDA feed of shortages and recalls round out the tools.

Yes. Pharmacists using Sig's Dose Adjustment tool check a whole medication list against kidney and liver function, weight, age, labs, and interacting drugs in one pass. As of November 3, 2026, our data hold 3,609 rules for 405 drugs. Each flag names the source FDA label or guideline beside the adjusted dose.

Clinical values entered in the tool are held in memory and discarded on leaving the tool. The app never sends the values anywhere.

For example, for a 78-year-old man weighing 62 kg with a serum creatinine of 2.2 mg/dL, Sig calculates a Cockcroft-Gault creatinine clearance (Cockcroft 1976) of 24 mL/min. Sig then flags gabapentin: reduce to approximately 200 to 700 mg once daily, the band for creatinine clearance from 15 to below 30 mL/min, according to the Dosage and Administration section of the FDA label.

Additionally, the flag lists what to monitor and the date the rule was last reviewed.

Yes. Sig's Antibiotic Selection tool suggests empiric therapy for 72 infection syndromes, targeted therapy from a culture result, and IV-to-PO and de-escalation options. Each option is checked against allergy, renal function, pregnancy, and QT. An institution's antibiogram, entered on the device, overrides the national defaults.

Additionally, 1,647 susceptibility breakpoints and 88 expert rules cover 121 organisms. The Antimicrobial Spectrum tool shows preferred, alternative, and limited-utility agents by organism or by drug.

Our data cover 72 syndromes and 42 pathogen-directed entries, last updated October 22, 2026.

For example, with an Escherichia coli blood culture, Sig asks whether the laboratory reports by CLSI or EUCAST breakpoints and whether the infection is deep-seated, then lists organism-directed options. The organism page also carries laboratory caveats, such as the FDA clearance note on the Verigene BC-GN panel, which does not distinguish E. coli from Shigella species.

Sig's calculator library is a set of more than 1,000 clinical calculators in 30 categories. For example: Cockcroft-Gault creatinine clearance (Cockcroft 1976), Child-Pugh, MELD 3.0 (Kim 2021), HAS-BLED (Pisters 2010), Wells criteria for PE and DVT, qSOFA, and the AHA PREVENT equations. Each result shows the inputs, the formula, and the citation on one screen.

Every calculator in the count has a working engine in the app. Our data show 1,013 of the 1,183 catalog entries (86%) have an engine, as of November 3, 2026. Additionally, entries without an engine are not counted, which is why the published number is lower than the catalog size.

A result can be shared through Apple's share sheet as text with the inputs, or as a link to get-sig.app opening the same calculator. Calculator inputs are held in memory on the device while the calculator is open and are discarded on closing.

No. Sig's Drug Interactions tool is a label check, not a severity-rated interaction database. Sig reads the current FDA label of each drug on a list, then finds mentions of the other drugs by name or by drug class. The FDA table of CYP and transporter substrates, inhibitors, and inducers backs the class matching.

For example, with simvastatin and clarithromycin on the same list, Sig shows the label sections of each drug mentioning the other or the other's class. Sections are quoted and ranked, with Contraindications before Drug Interactions. Additionally, our data add 1,499 rows of interaction guidance from HHS guideline tables, as of November 3, 2026.

The tool needs a connection to fetch labels from openFDA, and a drug with no openFDA label returns nothing. The list is kept for the session only and is never saved or sent anywhere else. Sig states the limits on the tool's own Sources and Limits page.

Yes. Sig's Pill Identifier searches 19,925 products by imprint, colour, and shape, or reads a photo of the tablet on the device. Scan Package reads the barcode on a box or takes a typed NDC and opens the current FDA label.

Images are analyzed on the device and are never saved to the photo library or uploaded.

For example, a pharmacist holding an unlabeled tablet can type the imprint and choose the colour and shape. Sig then lists each matching product with strength, labeler, and NDC. According to the app's sources, the imprint, colour, shape, score, and size data come from Structured Product Labeling published through DailyMed.

Our data come from the DailyMed archive of August 23, 2026. Additionally, imprints vary by manufacturer, so a match should always be confirmed against the dispensed product.

Yes. Sig bundles the FDA Orange Book edition of October 9, 2026. The Orange Book data include 48,865 products, therapeutic equivalence (TE) codes, reference listed drugs, 22,438 patents, and exclusivity. Sig also bundles the FDA Purple Book September 2026 release, with 2,251 biologic products, 100 biosimilars, and 146 interchangeables.

For example, opening a generic in the Orange Book shows the TE code, such as AB, and the reference listed drug the generic was rated against. Opening a biologic in the Purple Book shows the reference product and every biosimilar or interchangeable licensed against the reference, with what substitution means for each.

Additionally, pharmacists using Sig open both books from the Book button on the monograph of any listed drug, and both books work offline. Our data come from the FDA's own published files, and the edition date is shown in the app.

Yes. Sig's Controlled Substances tool lists 631 federal substances with DEA schedules, according to 21 CFR Part 1308 and 21 U.S.C. § 812. The tool adds the schedules of all 50 states and where each state differs from the federal list. Every entry is tied to the statute or rule cited.

For example, where a state schedules a substance differently from the DEA, Sig shows the state schedule with the statute setting the schedule. The tool also covers prescription rules from 21 CFR Part 1306 and who may prescribe controlled substances across ten professions in every state.

Additionally, pharmacists using Sig's DEA Number Check can validate a DEA registration number's letters and check digit, following the method in the DEA's own manual. The number is checked on the device and is never sent anywhere.

Our data for the federal and state schedules are current as of October 9, 2026.

Yes. Sig Translator is a tool for turning prescriber shorthand into plain patient directions. For example, "1 tab po bid x10d" becomes "Take 1 tablet by mouth twice a day for 10 days." Each expanded abbreviation is listed under the result, so a pharmacist using Sig Translator can see exactly how the label text was built.

The abbreviation table comes from named references, including the Joint Commission "Do Not Use" list, the ISMP List of Error-Prone Abbreviations, Symbols, and Dose Designations, FDA guidance on container labeling, and USP General Chapter <17> on prescription container labeling.

Our data draw on 10 published references for the abbreviations and the label wording, as of November 3, 2026.

Additionally, Sig Translator reads common pharmacy shortcut codes. The Day Supply tool then calculates days supply and NCPDP billing units for insulin pens, eye drops, inhalers, and topicals across 144 products, each tied to a published reference.

Sig is not designed to receive protected health information, so HIPAA obligations do not attach to Sig the way they do to a record system. Sig has no account, no analytics, and no server of its own. Values typed into a calculator stay on the device and are discarded on leaving the tool.

Additionally, HIPAA compliance is a property of how an organization handles patient data, not a certificate an app holds. Because Sig does not receive PHI, HARRIS CLINICAL SOFTWARE LLC is not a covered entity or business associate and does not sign business associate agreements.

Pharmacists using Sig should not enter names, dates of birth, or record numbers anywhere in the app. None of our data comes from patients. Every service the app contacts is named in Sig's privacy policy, effective November 2, 2026.

For example, according to HHS, the HIPAA Privacy Rule applies to covered entities, such as health plans and most health care providers, and to the business associates of covered entities.

Read the privacy policy

No, because Sig has no data flow for a business associate agreement to cover. A BAA governs vendors who create, receive, maintain, or transmit PHI for a covered entity. Sig does none of the four. Sig has no account, no analytics, no third-party SDK, and no Sig server for patient data to reach.

A security reviewer usually needs the data-flow answer, in three points. (1) Bundled content works offline. (2) Live lookups go from the device straight to named United States government services, such as the National Library of Medicine. (3) The only thing reaching us is a problem report a user chooses to send, encrypted first.

For example, a hospital IT reviewer working with Sig's privacy policy, effective November 2, 2026, can check each network request service by service. Our data contain no patient records, only published guidelines and FDA labeling. According to the policy, problem reports are deleted once resolved, and in any case within twelve months.

Network requests, service by service

Very little. Sig's bundled content works in airplane mode. When a pharmacist looks up something not bundled, such as a specific FDA label, an NDC, or a code, Sig sends only the query directly to the government service holding the record. No name, account, patient identifier, or calculator input is ever included.

Additionally, two other things can leave the device, both only on a user's action: (1) a Report a Problem submission, encrypted before sending, and (2) a result shared through Apple's share sheet. Sig downloads content updates from Apple, which carry no information about the user.

For example, opening the current label for a drug sends the drug's identifier directly to DailyMed or openFDA, per Sig's privacy policy, and nothing else. Our data flow is listed service by service in the privacy policy, effective November 2, 2026, and includes no account and no analytics.

No, and Sig will never require one. Sig has no sign-in, no Sign in with Apple, and no password, and the privacy policy makes the absence a commitment rather than a description. A planned optional subscription would be tied to the Apple Account through Apple's In-App Purchase, with nothing to sign in to.

The practical effect: there is no Sig account to be breached, sold, or subpoenaed.

Our data hold no user records at all. The no-account commitment sits in section 2 of the privacy policy, effective November 2, 2026.

For example, if Sig Pro launches as planned, a subscription bought on an iPhone would appear on the same person's iPad automatically, because Apple records the purchase against the Apple Account. Additionally, Restore Purchases would remain available as a fallback, and the app never asks for an email address or a password.

The no-account commitment

Turn the screenshot off, for example when a Dose Adjustment result shows a creatinine. Pharmacists using Sig's Report a Problem form, on every page, see the captured screen before anything is sent, with an Include Screenshot switch to remove the image. Reports carry no name, email address, or Apple Account and are encrypted on the device before leaving.

A pharmacist reads every report. According to Sig's privacy policy, effective November 2, 2026, reports are deleted when the problem is resolved, and in any case within twelve months.

In short: (1) tap Report a Problem on the page; (2) switch Include Screenshot off; (3) describe the error in words and tap Send. Each report records the page of origin, so the reviewing pharmacist can find the row without a screenshot.

Additionally, none of our data from a report identifies the sender.

Sig's content is written by a Doctor of Pharmacy and reviewed by two additional Pharm.D. reviewers. Every item a named reviewer has not yet cleared is labeled In Development in the app. Every data set shows the date of last review, so review status is visible rather than assumed.

Sig will be published only once the author is a registered pharmacist. A named reviewer roster and a public corrections log are part of the launch plan.

Our data show that 384 of the 384 guideline records (100%) still carry the In Development label while review continues, as of November 3, 2026.

For example, a dose rule a reviewer has not yet cleared shows In Development beside the rule, and the About and Sources screen lists each data set with a review date. Additionally, content corrections reported through Report a Problem are checked against the cited source before any fix.

Sig's primary source is FDA-approved labeling, taken through DailyMed and openFDA, plus 384 published guidelines and labels across 15 specialties. Drug names and classes come from RxNorm and RxClass (National Library of Medicine), prices from CMS NADAC, and lactation data from LactMed.

For example, a renal dose rule in Sig names the FDA label section behind the rule, such as Dosage and Administration (2.1). New guideline content is drafted from a verbatim quote of 25 words or fewer, and a machine check rejects any quote not found word for word in the source.

Our data show that 100% of the 15,497 recommendations name the source section, and 34% also give a page number, as of November 3, 2026.

Additionally, where practice diverges from the label, Sig calls out the divergence and cites the practice source rather than blending the two. When two documents give different numbers, each keeps a separate row with a separate citation. Where a source needs a number and prints none, Sig says so.

In Development means the item has been written and cited, but a named pharmacist reviewer has not yet cleared the item. The label is a signal to apply more of one's own scrutiny, not a statement the content is wrong. Sig shows review state openly, so a pharmacist can tell which parts have had a second review.

For example, a newly added guideline recommendation carries the In Development label until a named Pharm.D. reviewer checks the quote against the source document and clears the recommendation. Additionally, the About and Sources screen shows when each data set was last reviewed.

Our data show that 384 of the 384 guideline records (100%) carry the label today, as of November 3, 2026. Review is still in progress, and the label comes off an item only when a named reviewer clears the item.

Each bundled data set in Sig shows the date of last review. Dose rules, antimicrobial guidance, and boxed warnings are re-reviewed at least every six months. The counts on this site were taken from the app's catalogs on November 3, 2026.

Additionally, Sig is built so catalog corrections can arrive as signed content updates delivered through Apple. A correction then does not wait for an app update. Live data, for example labels, shortages, and recalls, reflects what the government service returned at the moment of the lookup.

The current editions in our data are: (1) the FDA Orange Book of October 9, 2026; (2) the FDA Purple Book release of September 2026; (3) the DailyMed archive of August 23, 2026 for pill identification; (4) federal and state controlled-substance schedules as of October 9, 2026.

No. Sig is reference and decision-support software for healthcare professionals and has not been reviewed or cleared by the FDA. Sig is built to sit within the clinical decision support description in section 520(o)(1)(E) of the Federal Food, Drug, and Cosmetic Act.

Any decision made by a pharmacist using Sig belongs to the pharmacist, under a personal license and judgment. Where Sig and the FDA-approved labeling or an institution's policy disagree, the labeling and the policy control.

Additionally, our data show the basis on every row: 100% of the 15,497 recommendations name the source section. The Terms of Use have stated that Sig is not a medical device since September 21, 2026.

For example, every Sig calculator result lists the inputs used, the method, and the citation, so the basis can be reviewed rather than trusted. According to the FDA's guidance on clinical decision support software, independent review by a healthcare professional is the criterion the design is built around.

Terms of Use

Sig is not yet on the App Store or in open beta. Sig will be released once the author is a registered pharmacist, expected after graduation in December 2026, and a TestFlight beta opens first. An email to support@get-sig.app joins the beta and brings word of the day Sig ships.

The waitlist is an email to us and nothing more: no account and no marketing list. Removal is available at any time on request.

To join: (1) send an email to the support address above; (2) accept the TestFlight invitation from Apple on arrival; (3) install the build and send feedback from inside the app.

For example, a beta tester receives an invitation through Apple's TestFlight app and installs the build. Additionally, the beta is free, and a tester can leave at any time by deleting the app or asking to be removed. Our data show the build already holds 15,497 recommendations and 434 decision trees, as of November 3, 2026.

Email to join the beta

Sig's core reference is planned to be free: monographs, calculators, dose adjustment, antibiotic selection, identification, conditions, guidelines, and the tools. An optional Sig Pro subscription is planned for workflow features such as watchlists and sync. Pricing is not final. Payment would go through Apple, so we would never see a card number.

For example, Dose Adjustment, Antibiotic Selection, the calculators, and the Orange Book are all part of the planned free core. Additionally, any subscription would be managed in the Apple Account settings on the device and could be cancelled at any time, according to Apple's subscription rules.

Our data show what the planned free core already covers, as of November 3, 2026: (1) 15,497 guideline recommendations; (2) more than 1,000 calculators; (3) dose rules for 405 drugs; (4) 559 curated monographs.

Sig runs on iPhone and iPad with iOS 27 and iPadOS 27, with a layout designed for each rather than one stretched to fit. On iPhone Duo, Sig opens across the fold without losing the reader's place, and on Macs with Apple silicon, Sig runs as the iPad app. Sig is not available for Android or Windows.

Sig supports Siri, Shortcuts, and Spotlight, Home Screen widgets, VoiceOver, Dynamic Type through the largest accessibility sizes, Reduce Motion, and Increase Contrast.

For example, on iPad the sidebar keeps Drugs, Conditions, Guidelines, Tools, and Updates in view while a condition page fills the detail column. Additionally, on the open iPhone Duo display, the Antimicrobial Spectrum shows the whole organism-by-antibiotic grid.

The screenshots on this site were captured from the current build in November 2026. Our data ship in the app bundle, so the 15,497 recommendations are the same on iPhone and iPad.

Yes. Sig publishes a subscribed calendar of 29 healthcare observances at webcal://get-sig.app/observances.ics. For example, American Pharmacists Month, National Pharmacy Week, and Pharmacy Technician Day appear with dates, and subscribers using Apple Calendar on iPhone, iPad, or Mac see the calendar refresh about once a week.

Every event is all-day and marked free, so the calendar never shows the subscriber as busy. Each event names the sponsoring organization and the dating rule, such as the third full week of October, so the date can be checked against the sponsor's own page.

Our data cover 29 observances, and the calendar file spans 2025 through 2030. Subscribing fetches one file from get-sig.app with no account or identifier. To stop, delete the Sig calendar in Calendar. Additionally, the same observances appear in the app's Healthcare Observances tool and widget.

Subscribe in Calendar

Yes. Feature requests and content corrections sent to support@get-sig.app are read by a pharmacist, and corrections reported from inside the app arrive through Report a Problem on every page.

Pharm.D. reviewers interested in a specialty are welcome to say which one. The reviewer roster is being built now, and named reviewers are credited in the app for the sections cleared. A public corrections log is part of the launch plan.

For example, a report of a wrong dose goes through three steps: (1) a pharmacist reads the report; (2) the pharmacist checks the claim against the guideline or FDA label the row cites; (3) the catalog changes only if the source supports the change, and the fix ships in the next build or content update.

Additionally, our data show the scale a reviewer would join: 15,497 recommendations from 384 guidelines and labels, as of November 3, 2026.

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