Chemistry subreddits
We found 25 active chemistry subreddits: communities with at least one new post a day on average in September 2026, ranked by members. The largest is r/chemistry with 3.89M members. It is also the busiest, with 878 posts last month. In 5 of the 12 we could measure, a brand-new account's post usually stays up: they remove 17% or fewer of posts from accounts under a week old.
Data for 25 communitiesDownload CSV
- r/chemistry3.89M members
- r/Chempros+96% members in 12 months
- r/OrganicChemistry16% of new-account posts removed
- r/chemhelp94% of posts get a reply
All active chemistry subreddits, by members
| # | Subreddit | Members | Posts / month | Member growth, 12 mo | Median author age | Women | Posts with a reply | New-account posts removed | Links |
|---|---|---|---|---|---|---|---|---|---|
| 1 | r/chemistry↗A community for chemists and those who love chemistry | 3.89M | 878 | +2% | 26 | 27% | 83% | 79% | Yes |
| 2 | r/Biochemistry↗A place to post news and discuss the frontiers of biochemistry and biotechnology. Please refrain from posting home videos with songs and raps. | 164K | 115 | +17% | 25 | 37% | 63% | 74% | Yes |
| 3 | r/chemistrymemes↗The Alchemist's Meme Lab A subreddit where science meets silliness! Dive into a bubbling cauldron of periodic puns, reaction-related roasts, and lab-life laughs. Whether you’re bonding over titration | 133K | 92 | +11% | 22 | 24% | 67% | 56% | Yes |
| 4 | r/OrganicChemistry↗new-account friendlySynthetic Organic Chemistry | 126K | 233 | +17% | 22 | 35% | 80% | 16% | Yes |
| 5 | r/chemhelp↗new-account friendlyr/chemhelp is place where you can seek help with whatever chemistry problem you may encounter. Whether you are a high school student trying to understand the fundamentals, a college student struggling | 117K | 522 | +16% | 22 | 34% | 94% | 9% | Yes |
| 6 | r/Chempros↗A subreddit for chemistry professionals. | 54K | 123 | +96% | 29 | 26% | 69% | 35% | Yes |
| 7 | r/crystalgrowing↗For all people who grow crystals as work, hobby or school science project. Show off your specimens! | 53K | 51 | +40% | 30 | 30% | 81% | – | Yes |
| 8 | r/AskChemistry↗new-account friendlyWe are chemists and scientists who help demystify molecular behavior and apply discipline to naughty, wayward reactions, with a dash of wit & humor. From basic principles to advanced topics, we welc | 53K | 274 | +48% | 31 | 21% | 76% | 14% | Yes |
| 9 | r/TheeHive↗This is a subreddit for all the lost Bees. You must read the rules. | 48K | 56 | +11% | 26 | 10% | 43% | Min. age/karma | Yes |
| 10 | r/cursedchemistry↗new-account friendlya place for all molecules that should not exist according to the basic chemistry rules | 46K | 105 | +45% | 25 | 20% | 83% | 3% | Yes |
| 11 | r/cursed_chemistry↗Featuring severe steric strain | 44K | 35 | +21% | 24 | 23% | 71% | – | Yes |
| 12 | r/ExplosionsAndFire↗The base of the YouTube/any video platform channel Explosions&Fire, where we do some chemistry, blow some stuff up and sometimes occasionally learn things. They deleted us once, let's do it all agai | 32K | 40 | +19% | 28 | 12% | 69% | – | Yes |
| 13 | r/homechemistry↗A subreddit for building your own lab at home and doing chemistry in it. | 29K | 80 | +71% | 32 | 13% | 62% | – | Yes |
| 14 | r/toxicology↗A place to discuss the ins and outs of the poisons world. Welcoming case studies, career advice, or any interesting toxicology topic. If you're anxious about your health, please seek help or vis | 23K | 62 | +46% | 31 | 42% | 74% | – | Yes |
| 15 | r/elementcollection↗This sub is dedicated to those who collect elements from the Periodic Table. As well as people who love to share their pictures, stories, etc.! So come on and join! | 21K | 107 | +67% | 31 | 14% | 87% | – | Yes |
| 16 | r/ALevelChemistry↗Help and resources for students taking A Level Chemistry. | 17K | 150 | +33% | 18 | 52% | 29% | 38% | Yes |
| 17 | r/PreciousMetalRefining↗Links and discussion relating to separating and extracting Precious Metals from other materials, such as electronics and jewelry. Usually the processes discussed here are for the home user to extract | 15K | 86 | +122% | 37 | 10% | 81% | – | Yes |
| 18 | r/APChem↗Come one, come all! /r/APChem encourages contribution and questions from anyone interested in chemistry, not just those in an AP course. | 14K | 79 | +35% | 17 | 46% | 74% | 19% | Yes |
| 19 | r/comp_chem↗new-account friendlyComputational Chemistry | 13K | 76 | +27% | 27 | 23% | 73% | 16% | No |
| 20 | r/PFAS↗A forum for discussion of all things related to PFAS, Per & Poly Fluoro Alkyl Substances, also known as "Forever Chemicals". | 12K | 30 | – | 37 | 37% | 60% | – | Yes |
| 21 | r/energetics↗A place to post energetic substances. High explosives preferred. Low explosives are subject to mod discretion. Please see rules before posting. | 12K | 43 | +150% | 31 | 10% | 85% | – | Yes |
| 22 | r/massspectrometry↗News and discussions for people involved and interested in mass spectrometry. | 11K | 54 | +24% | 32 | 28% | 74% | – | Yes |
| 23 | r/CHROMATOGRAPHY↗r/chromatography is the hub for all things chromatography, discussing techniques like HPLC, GC, TLC, and more, sharing protocols, troubleshooting separation issues, and exploring applications in pharm | 10K | 39 | +38% | 31 | 29% | 83% | 24% | Yes |
| 24 | r/radon↗Radon is an odorless, invisible, radioactive gas naturally released from rocks, soil, and water. Radon can get into homes and buildings through small cracks or holes and build up in the air. Over time | 10K | 86 | +65% | 38 | 19% | 90% | – | Yes |
| 25 | r/cosmeticscience↗Join us to talk about cosmetic science and technology. Topics include cosmetic science and technology, formulation, manufacture, testing, ingredients, trends, news, etc. | 4.9K | 71 | – | 28 | 73% | 34% | – | Yes |
Looking for a ranking by size and growth? Top chemistry subreddits by tier.
How this list is built
Subreddits are grouped into topics by what their posts are about; this list holds the chemistry group. We include subreddits that are safe for work and had at least 30 new posts in September 2026, about one a day.
Members is Reddit's subscriber count; growth compares it with a year earlier. Posts with a reply is the share of posts that got at least one comment over the last three months. Median author age and women are estimated from what authors say about themselves, and shown only when enough of them did. New-account posts removed is the share of posts from accounts younger than 7 days that were removed; communities at or below 17% are marked new-account friendly. Min. age/karma means the subreddit asks for a minimum account age or karma before you can post.
The list is rebuilt every month from public Reddit posts and comments. Data and CSV are free to reuse under CC BY 4.0 with a link to this page.
Chemistry subreddits: common questions
What is the biggest chemistry subreddit?
r/chemistry, with 3.89M members in September 2026. Next are r/Biochemistry (164K) and r/chemistrymemes (133K).
Which chemistry subreddits are the most active?
By posts in September 2026: r/chemistry (878 posts), r/chemhelp (522 posts) and r/AskChemistry (274 posts).
Which chemistry subreddits can a new account post in?
r/OrganicChemistry (16% of new-account posts removed), r/chemhelp (9% of new-account posts removed) and r/AskChemistry (14% of new-account posts removed). They ask for no minimum karma or account age, and most posts from accounts under a week old stay up.
How often is this list updated?
Every month, when we rebuild our subreddit data. This version uses data for September 2026. Member counts come from Reddit; activity, removals and who writes come from public Reddit posts and comments.
Find the subreddits that fit your post
This list is the same for everyone. Find Subs narrows it to communities your account can post in, where your audience writes, and tells you when to post.