Company lists · Data refreshed September 2026
Top 25 Custom synthesis companies based in the United Kingdom
RevenueBase identified 77 custom synthesis companies headquartered in the United Kingdom as of September 2026 and tracks 7,387 professional contacts across them, including 4,501 with verified work emails. London is the largest hub.
This list covers custom synthesis companies 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 September 19, 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.
The 25 largest custom synthesis companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 4,577 contacts → | ||||
Indirect evidence “Partnering to Advance Human Health A unique culture delivering exceptional solutions: Almac is a financially secure, privately owned organisation with 7,800+ employees globally.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 2 | 209 contacts → | ||||
Partial evidence “Concept Life Sciences is a knowledge-based, science-led and customer-focused contract research and manufacturing organisation with world-leading expertise in the pharmaceutical…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 3 | 160 contacts → | ||||
Indirect evidence “Lianhetech Seal Sands is a leading European contract manufacturer of high quality fine chemicals for use in the Crop Protection, Pharmaceutical and Performance chemicals markets.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 4 | 150 contacts → | ||||
Partial evidence “Briar Chemicals delivers contract and custom manufacturing solutions to customers across the globe.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 5 | 114 contacts → | ||||
Indirect evidence “CatSci Ltd is an award-winning innovation partner, dedicated to breaking down the silos in small molecules, TACS, glues and oligonucleotides CMC development to accelerate the…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 6 | 110 contacts → | ||||
Indirect evidence “Upperton Pharma Solutions is a specialist CDMO (contract development and manufacturing organisation) providing formulation and dosage form development and clinical trial…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 7 | 102 contacts → | ||||
Indirect evidence “Arcinova, A Quotient Sciences Company, is dedicated to providing innovative contract research, development, and manufacturing services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 8 | 87 contacts → | ||||
Indirect evidence “Thomas Swan & Co.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 9 | 86 contacts → | ||||
Indirect evidence “Onyx Scientific is a CDMO that helps pharmaceutical and biotech companies across the globe, accelerate candidates from discovery to manufacturing.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 10 | 84 contacts → | ||||
Indirect evidence “Fine Organics, a Lianhe Chemical Technology business, is a leading European contract manufacturer of high quality fine chemicals for use in the Crop Protection, Pharmaceutical and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 11 | 47 contacts → | ||||
Indirect evidence “We’re specialists in the manufacture and supply of aromatic, heterocyclic and aliphatic compounds, fluorochemicals and life sciences reagents, offering unrivalled service and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 12 | 44 contacts → | ||||
Indirect evidence “Molekula is a manufacturer and distributor of Fine Chemicals and Biochemicals in Bulk and Research quantities Founded in in France and the UK to initially support the Chemical…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 13 | 41 contacts → | ||||
Indirect evidence “Exwold is a contract chemical processing company based in the UK with decades of experience formulating and processing speciality chemicals for multi-national chemical and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 14 | 36 contacts → | ||||
Partial evidence “High Force Research specialise in chemical synthesis and R&D and offer chemistry built on many years of experience in development and scale-up of complex syntheses of molecules…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 15 | 34 contacts → | ||||
Indirect evidence “Endeavour Speciality Chemicals is an innovative UK-based manufacturer of speciality organic intermediates and together with our parent company Robinson Brothers we offer products…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 16 | 30 contacts → | ||||
Indirect evidence “Fluorochem is a leading supplier in the chemical industry, with nearly 60 years of experience supporting scientists in chemistry, pharmaceuticals and medicinal chemistry, and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 17 | 27 contacts → | ||||
Indirect evidence “Apex Molecular is a leading UK based Chemistry Services Contract Research Organisation based at Alderley Park, providing specialist chemistry services to the pharmaceutical…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 18 | 27 contacts → | ||||
Indirect evidence “Experts in Active Pharmaceutical Ingredients(APIs), Intermediates and other difficult to source Pharmaceutical ingredients- Cover APIs requirements from Development, Scale-Up and…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 19 | 23 contacts → | ||||
Indirect evidence “Key Organics is a leading UK-based chemistry CRO providing a range of discovery, research and development services to the international life sciences industries.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 20 | 21 contacts → | ||||
Indirect evidence “Glentham Life Sciences is a UK-headquartered supplier of fine chemicals, biochemicals and raw materials.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 21 | 21 contacts → | ||||
Partial evidence “Colour Synthesis Solutions (CSS) is a leading provider of fine chemicals and chemistry research and development services.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 22 | 20 contacts → | ||||
Indirect evidence “Established in 1996, Manchester Organics has grown into a world leader in fluorination and high pressure chemistry, research and manufacturing.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 23 | 19 contacts → | ||||
Partial evidence “Hypha Discovery is a specialist CRO with expertise in metabolite profiling (MetID), synthesis, purification and structure elucidation using NMR spectroscopy.” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 24 | 19 contacts → | ||||
Partial evidence “For the total GMP synthesis of complex carbohydrates and carbohydrate based medicinal chemistry, Dextra has a proven record of developing innovative solutions to minimise costs…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
| 25 | 18 contacts → | ||||
Indirect evidence “Witton Chemical Company specialises in the manufacture of fine chemicals and polymers, including product isolation and drying from flammable solvents, a variety of exothermic…” Source: RevenueBase Database · checked Sep 19, 2026Thanks. The Data Team will review it. | |||||
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: custom synthesis companies. 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 custom synthesis companies.
- Partial evidence
- Its own public description names part of custom synthesis companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name custom synthesis companies. 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 77 custom synthesis companies based in the United Kingdom
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Custom synthesis companies based in the United Kingdom at a glance
As of Sep 19, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 77 companies.
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 custom synthesis companies, 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 “custom synthesis companies”. 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 custom synthesis companies), 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 custom synthesis companies, 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, 4,501 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 September 19, 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.
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 custom synthesis companies, 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 custom synthesis companies are there based in the United Kingdom?
RevenueBase identified 77 custom synthesis companies headquartered in the United Kingdom as of September 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?
Almac Group, headquartered in Craigavon, tops this list with the largest team on record.
Which city has the most custom synthesis companies?
London leads with 7 headquartered companies, followed by Runcorn (3) and Glasgow (2).
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 4,501 verified decision-maker contacts tracked across these 77 companies.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 19, 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.
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