The process of developing a new drug is long and complicated. It can take over ten years and cost a lot of money—often billions. Let's break down the main steps involved:

1. Discovery and Preclinical Testing

• Finding a Target: Scientists look for a specific part of the body that is related to a disease.
• Testing Compounds: Thousands of different substances are tested to see which ones can work against the target. Sadly, only about 1 out of 5,000 will be successful.
• Preclinical Studies: Scientists do two kinds of tests—one in the lab (in vitro) and one in living organisms (in vivo). These tests help determine if the substance is safe and how it works in the body. Around 70% of drug candidates do not make it through this stage, mostly because they aren't safe or don’t work well.

2. Clinical Trials

Clinical trials have four main phases:

• Phase 1: This phase tests the drug on 20-100 healthy volunteers. The goal is to check safety, the right dose, and how the body processes the drug. Only about 10-15% of drugs go from this phase to being approved.

• Phase 2: This phase includes 100-300 patients to see if the drug works and what side effects it may cause. About 30% of drugs move on to Phase 3 after this testing.

• Phase 3: This larger trial includes 1,000-3,000 participants. Here, researchers confirm if the drug works well, watch for side effects, and compare it to existing treatments. Thankfully, 50-70% of drugs usually succeed in this phase.

3. Regulatory Review and Approval

• After trials show that a drug works and is safe, companies submit a New Drug Application (NDA) to the Food and Drug Administration (FDA) or similar groups. The review can take around 6 to 10 months.

4. Post-Marketing Surveillance (Phase 4)

• Even after approval, the drug is still watched closely to ensure it remains safe and effective. About 20% of drugs may need safety updates on their labels after they hit the market.

Summary

In short, developing a new drug takes a lot of time and money, averaging more than $2.6 billion and around 10-15 years from the first discovery to when it can be sold. Only about 1 in 10 drugs that start clinical trials end up getting approved. This whole process includes careful research, checks from authorities, and ongoing review to make sure medications are safe and effective for people to use.