Company lists · Data refreshed August 2026

Top 25 Clinical trial recruitment firms based in the United Kingdom

Name: Clinical trial recruitment firms based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Aug 31, 2026 212 companies tracked

RevenueBase identified 212 clinical trial recruitment firms headquartered in the United Kingdom as of August 2026 and tracks 10,379 professional contacts across them, including 4,927 with verified work emails and 1,882 with mobile numbers. London is the largest hub.

This list covers clinical trial recruitment firms headquartered in the United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed August 31, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list RevenueBase Smart Search rating on every row Refreshed Aug 31, 2026 86% judged on-target in blind review

212Companies

10,379Contacts tracked

4,927Verified emails

1,882Mobile numbers

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The 25 largest clinical trial recruitment firms based in the United Kingdom

Ranked by team size

Top 25 of 212 clinical trial recruitment firms based in the United Kingdom, ranked by team size, largest first. Data refreshed Aug 31, 2026. RevenueBase Smart Search rates how each company's information relates to clinical trial recruitment firms: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Premier Research	Partial evidence	Wokingham, United Kingdom	1,001-5,000	2,637 contacts →
	Partial evidence “Premier Research International LLC (Premier) is a global leader in clinical research and consulting services with expertise in driving an efficient and effective path to market…” Source: RevenueBase Database · checked Aug 31, 2026
2	Perceptive INC	Partial evidence	London, United Kingdom	1,001-5,000	1,197 contacts →
	Partial evidence “Expanding on their combined 50-year history, Perceptive provides best-in-class specialist support to global pharmaceutical, biotech, and clinical research organizations, spanning…” Source: RevenueBase Database · checked Aug 31, 2026
3	Endpoint Clinical	Strong evidence	London, United Kingdom	501-1,000	623 contacts →
	Strong evidence “Clinical trials are designed around endpoints, but it’s the beginning that sets them up for success-including selecting the best RTSM partner for continuous and flexible support…” Source: RevenueBase Database · checked Aug 31, 2026
4	Nucleus Network	Strong evidence	London, United Kingdom	501-1,000	572 contacts →
	Strong evidence “Nucleus Network is the only global provider dedicated to early phase clinical trials, with units in Australia, the USA and the UK.” Source: RevenueBase Database · checked Aug 31, 2026
5	Citeline	Strong evidence	London, United Kingdom	501-1,000	475 contacts →
	Strong evidence “At Citeline (a Norstella company), we are a global leader in clinical trial intelligence, data, and insights for the life sciences and pharmaceutical industries.” Source: RevenueBase Database · checked Aug 31, 2026
6	CALYX	Indirect evidence	Nottingham, United Kingdom	1,001-5,000	457 contacts →
	Indirect evidence “Calyx and Invicro are now Perceptive!” Source: RevenueBase Database · checked Aug 31, 2026
7	Phastar	Indirect evidence	Glasgow, United Kingdom	501-1,000	383 contacts →
	Indirect evidence “Phastar is an award-winning specialist biometrics and data science CRO, trusted by pharma, biotech, and medical device companies worldwide.” Source: RevenueBase Database · checked Aug 31, 2026
8	MAC Clinical Research	Strong evidence	United Kingdom	201-500	347 contacts →
	Strong evidence “MAC Clinical Research is a leading full-service, global Contract Research Organisation (CRO) with over 30 years of experience in clinical trial management.” Source: RevenueBase Database · checked Aug 31, 2026
9	Tech Observer	Indirect evidence	Manchester, United Kingdom	501-1,000	332 contacts →
	Indirect evidence “Global Reach; Local Expertise Headquartered in Paramus, New Jersey, USA with offices in Singapore, Denmark, UK, and India, our exceptional team of 500+ professionals serves…” Source: RevenueBase Database · checked Aug 31, 2026
10	Simbec-Orion	Indirect evidence	Tydfil, United Kingdom	201-500	308 contacts →
	Indirect evidence “Our passion for improving patients’ lives motivates us to apply our skills, experience, and knowledge to advance medicine.” Source: RevenueBase Database · checked Aug 31, 2026
11	Theorem NOW Fortrea	Indirect evidence	Slough, United Kingdom	10001+	286 contacts →
	Indirect evidence “We are now Fortrea.” Source: RevenueBase Database · checked Aug 31, 2026
12	HVIVO	Partial evidence	London, United Kingdom	51-200	213 contacts →
	Partial evidence “hVIVO plc (Ticker: HVO) is a science‑led early‑phase drug development company purpose‑built to meet the growing complexity of modern clinical research.” Source: RevenueBase Database · checked Aug 31, 2026
13	Richmond Pharmacology	Indirect evidence	London, United Kingdom	51-200	203 contacts →
	Indirect evidence “At Richmond, we're on a mission to transform healthcare by delivering faster answers and turning hope into tangible solutions.” Source: RevenueBase Database · checked Aug 31, 2026
14	SCOUT	Strong evidence	London, United Kingdom	201-500	168 contacts →
	Strong evidence “Scout proudly celebrates over 30 years of empowering clinical trials with people-first solutions and industry-leading tech.” Source: RevenueBase Database · checked Aug 31, 2026
15	Link Medical	Indirect evidence	London, United Kingdom	51-200	146 contacts →
	Indirect evidence “Since our founding in 1995, LINK Medical has been a trusted partner for Biotech, Pharma, and MedTech companies across the Nordics and beyond.” Source: RevenueBase Database · checked Aug 31, 2026
16	Panthera Biopartners	Partial evidence	Preston, United Kingdom	11-50	128 contacts →
	Partial evidence “Panthera is an independent SMO working with pharmaceutical and contract research organizations to find the right patient, for the right trial, at the right time through the…” Source: RevenueBase Database · checked Aug 31, 2026
17	Medicines Evaluation Unit Ltd, An Iqvia Business	Indirect evidence	Manchester, United Kingdom	51-200	96 contacts →
	Indirect evidence “The Medicines Evaluation Unit (MEU) Ltd, an IQVIA business, is one of the UK’s leading contract research organisations, a facility where commitment to excellence is paramount.” Source: RevenueBase Database · checked Aug 31, 2026
18	ARC Regulatory	Strong evidence	Belfast, United Kingdom	11-50	43 contacts →
	Strong evidence “ARC's purpose is to expedite access to precision medicine clinical trials for patients globally.” Source: RevenueBase Database · checked Aug 31, 2026
19	Ellipses Pharma	Partial evidence	London, United Kingdom	51-200	40 contacts →
	Partial evidence “Ellipses Pharma is an international drug development company, focused exclusively on the advancement of innovative cancer treatments through the clinic.” Source: RevenueBase Database · checked Aug 31, 2026
20	Esms Global LTD	Indirect evidence	London, United Kingdom	51-200	37 contacts →
	Indirect evidence “Described as "A centre of excellence" by the MHRA - ESMS Global LTD, formerly part of the Guy’s Poisons Unit, is a niche service provider based in central London.” Source: RevenueBase Database · checked Aug 31, 2026
21	Atlantic Research Group	Partial evidence	Leatherhead, United Kingdom	51-200	33 contacts →
	Partial evidence “ARG is now part of Evestia Clinical.” Source: RevenueBase Database · checked Aug 31, 2026
22	Research Grid R.Grid	Strong evidence	Norwich, United Kingdom	51-200	25 contacts →
	Strong evidence “Research Grid (R.grid) are the experts in automating clinical trials.” Source: RevenueBase Database · checked Aug 31, 2026
23	Albion RYE Associates	Partial evidence	Redhill, United Kingdom	11-50	24 contacts →
	Partial evidence “Albion Rye Associates are global single sector, life sciences recruitment experts, dedicated to supporting clients in their mission to positively impact, and improve patient lives…” Source: RevenueBase Database · checked Aug 31, 2026
24	Antidote Technologies	Partial evidence	London, United Kingdom	11-50	24 contacts →
	Partial evidence “Antidote is on a mission to catalyze medical innovation by successfully connecting patients and researchers as the best-in-class recruiter for clinical studies.” Source: RevenueBase Database · checked Aug 31, 2026
25	Research Organisation KC LTD	Strong evidence	London, United Kingdom	11-50	23 contacts →
	Strong evidence “ROKC is an innovative CRO specialising in the bespoke design, management and delivery of Pan European multi-centre clinical trials to commercial, academic and non governmental…” Source: RevenueBase Database · checked Aug 31, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: clinical trial recruitment firms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names clinical trial recruitment firms.
Partial evidence: Its own public description names part of clinical trial recruitment firms, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name clinical trial recruitment firms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 212 clinical trial recruitment firms based in the United Kingdom

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Clinical trial recruitment firms based in the United Kingdom at a glance

As of Aug 31, 2026

47.5%Verified-email coverage

18.1%Mobile-number coverage

49.0Average contacts per company

1-10Median size (employees)

34.0%Largest-city concentration · London

Aug 31, 2026Page data refreshed

Companies by employee count

1-10

117

11-50

51-200

201-500

501-1,000

1,001-5,000

10001+

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among clinical trial recruitment firms, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United Kingdom whose own description of what they do matches “clinical trial recruitment firms”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names clinical trial recruitment firms), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among clinical trial recruitment firms, and records with no verified work email. Companies headquartered outside United Kingdom are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 4,927 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on August 31, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Clinical trial recruitment firms by metro

Clinical trial recruitment firms in London72

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names clinical trial recruitment firms, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many clinical trial recruitment firms are there based in the United Kingdom?

RevenueBase identified 212 clinical trial recruitment firms headquartered in the United Kingdom as of August 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Premier Research, headquartered in Wokingham, tops this list with the largest team on record.

Which city has the most clinical trial recruitment firms?

London leads with 72 headquartered companies, followed by Manchester (12) and Glasgow (8).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,927 verified decision-maker contacts tracked across these 212 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on August 31, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.