A medicine can be safe for a patient but still cause problems after it leaves the body. Some of its ingredients pass into wastewater when people use the toilet. From there, they can reach rivers, where they may affect fish and other aquatic life.

The problem is that this information is not always easy to find. Scientists publish detailed findings, but doctors and pharmacists rarely have time to search through technical reports when helping a patient choose a treatment.

Germany wants to make that job easier. In May 2026, the German Environment Agency (UBA) published a feasibility study for a proposed environmental rating system for medicines. The idea is to give healthcare professionals a clearer picture of what researchers know about the environmental effects of different medicines.

That sounds simple enough. In practice, though, the system needs to answer some difficult questions. How should scientists rate an ingredient when the evidence is incomplete? What does a green rating actually mean? & how can doctors use this information without putting a patient’s health second?

Why Germany wants a clearer picture of medicines in the environment

When someone takes a medicine, the body may break down some of its ingredients. However, it does not always remove them completely. Some ingredients leave the body through urine & enter the sewage system.

Wastewater treatment plants remove many unwanted substances. However, some medicine residues can pass through the treatment process & enter rivers, lakes & other waterways. Their effects depend on the substance itself, how much reaches the water & how long it remains there.

Researchers have already found hundreds of pharmaceutical substances in the environment. According to the UBA, monitoring has detected at least 414 substances, including active ingredients, their breakdown products & other related compounds.

That figure needs a little context. Finding a medicine residue in a river does not automatically mean it has harmed wildlife. Scientists must look at the amount present & compare it with evidence about its effects on living organisms.

The scale of the task is another concern. Around 2,500 active substances are used in human medicines in Germany. The UBA estimates that roughly half may need a closer environmental assessment under the criteria it examined.

Looking into each substance takes time. Researchers may need to compare laboratory studies, check how quickly an ingredient breaks down & work out whether the available evidence reflects what happens in real waterways.

A proposed environmental rating system for medicines could make these findings easier to use. Instead of expecting a doctor to read several research papers, the system could present the main findings in one place.

That does not mean environmental concerns should decide which medicine a patient receives. It means healthcare professionals could have more information when two treatments are already suitable for the same person.

What the Arzneimittelindex Umwelt could look like

The proposed Arzneimittelindex Umwelt would make environmental information about medicines easier to find. The UBA study looks at how a central source could bring together existing evidence & present it in a way that people outside scientific research can understand.

One option is to use the ChemInfo database to make the information available. The study also considers ways to bring it into tools that healthcare professionals already use.

The proposed environmental rating system for medicines would use four colours to classify medicines:

• Red: The available evidence points to a strong environmental concern.
• Yellow: The ingredient raises concerns that users should consider.
• Green: The assessment points to a lower level of concern under the method used.
• Grey: There is not enough information to give the ingredient a clear rating.

These colours may look familiar, but users will need clear explanations of what each one means.

For example, green would not mean that an ingredient has no environmental effects. It would mean that the evidence points to lower concern under the assessment method. Grey would not mean that an ingredient is safe, either. It would show that researchers cannot reach a clear conclusion with the information available.

The UBA study also gives early estimates of how the proposed model might classify ingredients. It places around 1,650 in the green category, 50 in red & 780 in grey.

These figures come from the model examined in the study. They are not final ratings for every medicine sold in Germany.

The large grey group is worth watching. If researchers do not have enough information about an ingredient, the system needs to make that gap clear. A colour should not give users more confidence than the evidence deserves.

Where the information appears will matter just as much. The study considers databases, pharmacy software & tools used in medical practices. If doctors have to open another website every time they prescribe a medicine, many may struggle to use the ratings during a busy working day.

How scientists assess the environmental risk of medicines

Not every medicine ingredient behaves the same way once it enters the environment. Some break down quickly in water. Others stay there for longer & may expose fish and other aquatic life to the substance over time.

Scientists need to look at more than whether an ingredient can cause harm. They also need to understand how much of it may reach rivers, how long it stays there & what research says about its effects.

When assessing an ingredient, they may look at:

• How harmful it can be: Can it affect fish, algae, or other aquatic life?.
• How much reaches the water: Does the substance enter the environment at levels that could cause concern?.
• For how long it stays there: Does it break down quickly, or can it remain in the water?
• What the research shows: Have scientists studied its effects in enough detail, or are important questions still unanswered?

These details help explain why two ingredients may receive different ratings. They also show why a colour on its own cannot tell the whole story. Users need to understand what the rating means & whether researchers have enough evidence to support it.

The same applies when comparing medicines. A medicine used to treat one condition cannot always be compared fairly with one used for something completely different. The more useful comparison is between two treatments that a doctor could reasonably prescribe for the same patient.

Even then, the environmental rating is only one part of the decision. If one medicine works better for the patient or causes fewer side effects, that matters more than a more favourable environmental rating.

Could environmental ratings affect what doctors prescribe?

The idea is to give doctors useful environmental information without adding another task to an already busy day. If they have to leave their prescribing software, open a separate database & search for every medicine, the ratings may not get much use.

The UBA study looks at ways to make the information available through existing tools, including databases and software used by doctors and pharmacists. If the ratings appear alongside the usual medicine information, healthcare professionals could check them when comparing treatment options.

For example, imagine a patient can take either of two medicines. Both are suitable, but one has a lower environmental concern rating. That information could help the doctor weigh up the options.

Now imagine the patient has already tried one of those medicines & suffered serious side effects. The doctor may have a clear reason to choose the other treatment, regardless of its environmental rating. The patient’s health still comes first.

This is the thinking behind eco-directed prescribing: considering environmental effects when there is a genuine choice between suitable treatments. It does not mean asking patients to accept a medicine that works less well just because it appears better for the environment.

Doctors will also need to know why a medicine received its rating. A colour without an explanation may raise more questions than it answers. They need access to the evidence behind it, along with any gaps or uncertainties that could affect the result.

The proposed environmental rating system for medicines has not yet shown that it will change prescribing habits. The ratings will only be useful if doctors can access them easily & understand how to use them when choosing between treatments.

Where colour ratings have their limits

A colour can tell you a lot at a glance, but it cannot explain everything behind a medicine’s environmental rating.

Some ingredients have been studied extensively, so researchers have a clearer idea of how they behave in water & whether they can harm aquatic life. Others have barely been studied. In those cases, researchers may not have enough evidence to say how much of a concern the ingredient poses.

This is why the proposed ​​environmental rating system for medicines includes a grey category. It flags medicines where the available information isn’t enough to assign a clear rating. A grey rating does not mean the ingredient is safe. It means researchers need more evidence before they can draw a firm conclusion.

Ratings may also need to change as new research becomes available. An ingredient assessed several years ago might look different once scientists have more data on its effects. The system will need a way to update ratings rather than leave old assessments in place indefinitely.

There is another thing to remember: a medicine’s environmental rating will not necessarily cover its entire environmental footprint.

For example, researchers might assess what happens to an active ingredient after a patient takes the medicine. That assessment would not necessarily include the energy used to make the product, its packaging, or the emissions from transporting it. These are separate parts of a medicine’s environmental impact.

The UBA’s early estimates put around 780 ingredients in the grey category under the model it examined. That’s a sizeable group for which the proposed environmental rating system for medicines could not provide a clear rating. Germany will need to work out how to address these gaps & keep the assessments up to date as more research becomes available.

What the proposal means for pharmaceutical companies

Pharmaceutical companies do not automatically face new legal duties because of this proposal. However, they can start looking at the environmental data they already have for their products.

That information may be spread across different departments. Research teams might hold study results, regulatory teams may manage assessment records & sustainability teams may track the company’s wider environmental work. Until these records are brought together, it can be difficult to see what the company knows about each ingredient & where information is missing.

Companies can start with a few basic checks:

• Available data: What environmental studies are available for each active ingredient?
• Missing information: Which ingredients have limited evidence or assessments that may need updating?
• Responsibility: Who will keep the records current as new research becomes available?
• Communication: Can teams explain the findings clearly, including what remains uncertain?

This review is useful beyond the proposed rating system. It can help companies understand the environmental questions linked to their products & prepare to respond if the environmental rating system for medicines moves forward.

Manufacturing is only one part of the picture. Companies can reduce factory emissions, improve wastewater treatment & cut waste, but those steps do not tell them everything about what happens to an ingredient after a patient takes a medicine.

These are separate issues. Manufacturing controls focus on releases from production sites. An assessment of an active ingredient looks at its possible effects once it enters the environment during use / after use.

An environmental rating system for medicines will not solve pharmaceutical pollution in Germany by itself. Better information can help identify concerns, but Germany will still need suitable wastewater treatment, safe disposal of unused medicines & further research into substances with limited data.

Companies should also avoid assuming that a better environmental rating will automatically improve sales, reimbursement or market access. The proposal does not establish that. Any effect on commercial decisions would depend on how the system develops & whether healthcare professionals use the ratings.

For now, companies do not need to make product changes based on a proposed system that is still being developed. Reviewing their existing data, identifying gaps & assigning responsibility for updates would be a more useful first step.

What Germany can learn from Sweden

Germany is not starting from scratch when it comes to environmental information about medicines. Sweden already provides this type of information through resources such as Janusinfo.

The point is not that Germany should copy Sweden’s approach exactly. It is that healthcare professionals need more than a colour or a score. They need to be able to check what the assessment is based on & understand where the evidence has limits.

How easily people can access that information matters, too. A resource may contain useful research, but it will have limited value if doctors and pharmacists struggle to find it during their working day.

Germany will need to consider how the proposed ratings fit into its own prescribing tools, pharmacy systems & professional guidance. The environmental rating system for medicines also needs to make sense to the people expected to use it.

The key question is straightforward: will the information help healthcare professionals compare suitable medicines more confidently? Publishing ratings is a start, but their value will depend on whether people can understand them & use them in practice.

What pharmaceutical companies should watch next?

The UBA’s May 2026 study gives Germany a possible route forward, but several details still need to be settled. Pharmaceutical companies should watch for updates on the rating method, the evidence used to classify ingredients & how healthcare professionals will access the results.

The study suggests that adding environmental information to ChemInfo within the next 24 months could be realistic. That is a suggested timeframe, not a confirmed launch date or legal deadline.

Companies can use the time to review their environmental records & identify where better evidence may be needed. They can also consider how to make this information easier for their regulatory, research & sustainability teams to share.

These issues are part of a wider discussion about how the life sciences industry can reduce its environmental impact. The 5th Net-Zero Life Sciences Forum 2026 will take place on 12–13 November 2026 at the Crowne Plaza Düsseldorf – Neuss Hotel in Düsseldorf, Germany. The forum will cover practical approaches to decarbonisation, energy resilience, Scope 3 emissions & investment decisions.

For pharmaceutical and other life sciences companies, it offers an opportunity to discuss how environmental targets can translate into changes across their operations.

Frequently asked questions

What is the Arzneimittelindex Umwelt?

The Arzneimittelindex Umwelt is a proposed environmental rating system for medicines that would make environmental information about medicines easier to access. It could use four colours to show whether the available evidence points to a concern, lower concern, or a lack of enough data. Doctors and pharmacists could use this information when comparing suitable treatments, but it would not replace clinical judgement.

Is Germany’s environmental rating system for medicines already operational?

No. In May 2026, the UBA published a feasibility study exploring how the system could work. The study examines a possible rating method & ways to share the information through existing databases and healthcare software. A national rating service is not confirmed as operational, and the final method and implementation plans still need to be established.

Will environmental ratings decide which medicines doctors prescribe?

No. The ratings would give doctors additional information, not tell them which medicine to choose. They would still need to consider how well a treatment works, its side effects & the patient’s medical history. An environmental rating may help when two treatments are equally suitable, but it should not outweigh a clear medical reason to choose one over the other.