Roundup weed killer: one brand name, five different chemistries
Roundup is not a product, it is a badge on twenty-one separate authorisations. Some are glyphosate, some are pelargonic acid, one is vinegar in a fancy bottle, and the front of the pack does not tell you which. Here is every UK Roundup decoded by active ingredient, MAPP number and whether it reaches a root.
By The Weed GuyLast updated
The short version
Ask whether Roundup contains glyphosate and the honest answer is that it depends which bottle you picked up. Fast Action, Tough, Optima+, Ultra and Stump Killer are glyphosate, running from 7.2 g/L to 360. Total Optima and Path Optima are pelargonic acid. Speed Ultra is acetic acid. The lawn line is different chemistry again. Only the glyphosate ones reach a root, and the manufacturer tells you which is which nowhere on the front of the pack.
Every Roundup, and what is actually in it
Read off HSE's registers on 14 August 2026. Neither the retailers nor the manufacturer put these side by side.
| Product | Active ingredient | Reaches the root? | MAPP |
|---|---|---|---|
| Roundup Fast Action Ready to Use | 7.2 g/L glyphosate | Yes, systemic | 18679 |
| Roundup Tough Ready to Use | 7.2 g/L glyphosate | Yes, systemic | 18693 |
| Roundup Optima+ Concentrate | 170 g/L glyphosate | Yes, systemic | 18846 |
| Roundup Ultra Concentrate | 360 g/L glyphosate | Yes, systemic | 18850 |
| Roundup Stump Killer | 360 g/L glyphosate | Yes, systemic | 18849 |
| Roundup Weedkiller Path Optima | 43.1 g/L pelargonic acid | No, contact only | 20722 |
| Roundup Weedkiller Total Optima | 43.1 g/L pelargonic acid | No, contact only | 20721 |
| Roundup Total Optima Concentrate | 565.49 g/L pelargonic acid | No, contact only | 20719 |
| Roundup Speed Ultra | 60 g/L acetic acid | No, contact only | 18692 |
| Roundup ProActive (professional only) | 360 g/L glyphosate | Yes, systemic | 21225 |
Nine of those ten are the ones you will meet on a shelf. ProActive is the tenth, and it sits on the professional register rather than the home garden one. Behind the nine, the home garden register carries twelve more Roundup authorisations: three weedkiller gels, a Path and Drive concentrate at 170 g/L glyphosate, the NL Weed Control pair on pelargonic acid, a Path Optima concentrate, and five lawn products running on clopyralid, fluroxypyr, MCPA, dicamba and mecoprop-P. Lawn treatments are out of what I cover here, but they are worth knowing about for one reason: they mean the word Roundup on a British shelf currently spans five separate chemistries.
The brand's own website sorts by job, never by chemistry
This is not a shopper being careless. It is the way the range is presented, and I went and checked rather than assuming.
The official Roundup UK site lists fifteen products and sorts them into four tiles: All Purpose, Path Patio and Drive, Beds and Borders, and Tough Weeds. Not one active ingredient appears anywhere on that page. The actives exist, but they live inside a Details and Usage block on each individual product page, one product at a time, so you can only ever read them one after another and never against each other.
The consequence is the thing worth spelling out. Because the sorting is by job rather than by chemistry, two products sitting in the same category can be completely different herbicides. Path Optima and the Path and Drive line share a tile and share nothing else. A shopper who correctly identifies the job they are doing, picks the right tile and buys from it has still not been told whether the thing in the bottle can reach a root.
The trade side of the same brand behaves differently, incidentally. Every professional listing I looked at states 360 g/L glyphosate on the face of it, because the buyer is assumed to be comparing actives. It is only the garden range that leaves it out.
Fast Action is the slow one, and Speed Ultra never gets to the root
Put the two names in front of anyone and they will tell you Speed Ultra is the quicker version of Fast Action. They are not the same chemical, they are not doing the same job, and the one named for speed is the one that leaves the plant alive.
Roundup Fast Action is 7.2 g/L glyphosate. Its own product page promises results visible in one to two days, then adds that effects can take from a few days up to four weeks depending on weather and weed. That second sentence is the true one. Glyphosate is slow because it is being carried down inside the plant into the root system, which is the whole reason it works.
Roundup Speed Ultra is 60 g/L acetic acid, and the manufacturer says first visible results can show within an hour. Total Optima, on pelargonic acid, claims results in three hours and dead weeds inside a day. Both are true, and both are describing the same thing: the tissue the spray physically wetted collapsing. Nothing has travelled anywhere.
So the honest reading is that these bottles are sold on how fast the damage becomes visible, and the fastest ones are fast precisely because they stop at the surface. If you want to know why a weed that browned off in an afternoon is back in a fortnight, that is the systemic and contact split in one bottle range.
The manufacturer already tells you which ones finish the job
There is one number on these packs that settles the argument without any chemistry at all, and almost nobody reads it. It is the maximum number of treatments a year.
Roundup Fast Action states a maximum of one treatment per year. Roundup Weedkiller Total Optima, Path Optima and Speed Ultra all state a maximum of four applications per year. Same brand, same shelf, four times the permitted frequency on the ones sold for speed.
A herbicide that finishes what it starts does not need a schedule. One that browns the leaf and leaves an intact root does, and the label is quietly building that repeat visit into the permitted use. Read those two numbers as a forecast of your summer rather than a safety limit, and the choice makes itself.
The plus sign is the glyphosate
Of all the ways this range can catch you out, this is the one I would put money on. There are four Optima products on a garden shelf and the difference between them is a single character.
Roundup Optima+ Concentrate is 170 g/L glyphosate acid under MAPP 18846, a genuine systemic that makes up to 50 spray litres from a 1 litre bottle and covers up to 1,500 square metres. Roundup Weedkiller Total Optima under MAPP 20721 and Roundup Weedkiller Path Optima under MAPP 20722 are both 43.1 g/L pelargonic acid, and contain no glyphosate whatsoever.
To the manufacturer's credit, Total Optima does say "No glyphosate" on the front, and files itself under glyphosate-free weed control. That is honest labelling. The problem is what a shopper does with it, because "no glyphosate" reads as a safety upgrade when what it actually describes is a change of mechanism. You have not bought a gentler version of the same thing. You have bought a chemical that cannot do the job the brand is famous for.
And if you are looking for the biggest number in the whole range, it is not on a glyphosate bottle. Roundup Total Optima Concentrate is registered at 565.49 g/L pelargonic acid under MAPP 20719, well clear of Ultra's 360 g/L glyphosate. Grams per litre only ever compare products sharing an active ingredient, which is exactly why the g/L figure has to be read alongside the active it belongs to.
Path Optima is not approved for most paths
If you are treating a drive, this is the one to know about.
Roundup Weedkiller Path Optima sits in the manufacturer's Path, Patio and Drive category. Its own description puts it on gravel areas, permeable paths, driveways, patios overlying soil and along fences. Then the safety instructions say not to apply it to impermeable hard surfaces such as asphalt, concrete, cobblestones, tarmac, paving and patio, or to any other situation with a high risk of run-off.
Work through what that leaves. A sealed block-paved drive, a concrete path, a tarmac apron and a flagged patio are all named in the exclusion. The bottle called Path is approved for the soft, permeable, free-draining half of the category it is sold in, and ruled out on the hard half, which is the half most people are standing on when they decide they need weedkiller.
The reason is run-off rather than danger. An acid on an impermeable surface does not soak in, it runs to the nearest gully. But the practical effect on a shopper is the same: you can buy the correctly categorised product for your driveway and find its own instructions rule your driveway out. If a paving joint is the actual problem, the joint itself is what needs dealing with, rather than only what is growing out of it.
There is no such thing as the Roundup instructions
Searches for how to use it treat the brand as one product with one method. Across this range the dose, the rain window, the replanting interval and the number of goes you get all change with the bottle.
Take the rain window first, because it is the one people lose a whole treatment to. Fast Action, Optima+ and Ultra all say rain within six hours of spraying reduces effectiveness and may mean repeating the job. Total Optima and Path Optima say to reapply if it rains within three hours. Same brand, half the margin, and no way to know which applies without the pack in your hand. There is more on what rain actually does to a fresh spray if you have already been caught by it.
Then the size question, which is where the money goes. Bottle volume tells you nothing about coverage in this range. Fast Action comes as 1 litre and 3 litre ready-to-use packs and is mostly water by design. Ultra Concentrate comes in 500ml and 1 litre, and the 1 litre makes up to 100 spray litres covering up to 3,000 square metres. Optima+ is 280ml and 1 litre, the litre making up to 50 spray litres over 1,500 square metres.
Put the two extremes together and the gap is hard to believe. A 1 litre Path Optima treats up to 33 square metres. A 1 litre Ultra Concentrate treats up to 3,000. Same brand, same size bottle, roughly ninety times the ground, and the only thing separating them on a shelf is the wording. Anyone weighing a 5 litre ready-to-use pack against a small concentrate should work through what a litre of each really costs by the gram of active ingredient before deciding which is the big bottle.
One thing I could not pin down, so I am saying so rather than filling the gap. The retail range includes a Fast Action Path and Drive ready-to-use pack, and I could not match it to a register entry with any confidence. The nearest thing on the register is Path and Drive Roundup Concentrate under MAPP 18844, at 170 g/L glyphosate, and that is a concentrate rather than a ready-to-use. Check the MAPP number printed on the pack.
Roundup ProActive: the professional one is exactly the same strength
People search for ProActive because they assume the version the councils spray is a different order of thing to the bottle in the garden centre. On concentration, it is identical.
Roundup ProActive is 360 g/L glyphosate, a soluble concentrate registered under MAPP 21225 and held by Bayer CropScience, first authorised in June 2025. Roundup Ultra Concentrate is also 360 g/L glyphosate, under MAPP 18850, and it sits on the home garden register where anyone can buy it without a certificate or a trade account. The number everybody chases is already on the amateur shelf.
What the professional label actually buys is a bigger pack, its own set of approved use areas, and a legal obligation. A professional-use product may only be bought for, and used by, someone holding the specified certificate of competence or working under their supervision, and that applies on your own driveway as much as on a council pavement. Trade sellers make you confirm you understand that before they will take an order. The full position on where the legal ceiling actually sits is worked through separately.
One footnote for anyone cross-checking. There are two generations of professional Roundup registrations. The older Monsanto-held ProActive under MAPP 17380 runs to 31 January 2029, and the Bayer replacements under the 212xx numbers were authorised in 2025. Both are 360 g/L. If you are quoting a MAPP number for ProActive today, it is 21225.
Is Roundup banned in the UK?
No. Every product on this page was authorised and legally on sale in August 2026 on HSE's register. The ban stories are mostly about somewhere else: Guernsey, France, a 2018 story about retailers reviewing their ranges, and a long-running American court case. None of those is a British ban.
Two register details are worth knowing, and neither is what people expect. The first is that every Great Britain amateur glyphosate Roundup currently shows an expiry date of 09/09/2099. That is not a hundred-year approval. HSE's own note on the results page says it means an extension has been applied under Article 43 and the authorisation will be withdrawn once a regulatory decision is taken. In plain terms, those products are on a holding pattern with no fixed end date.
The second detail runs the opposite way to the assumption. The Roundups that do carry real end dates are the ones with no glyphosate in them. The pelargonic acid products, Total Optima and Path Optima included, expire on 01/06/2029. Speed Ultra expires on 31/05/2029, and it is named among around thirty amateur acetic acid products on HSE amendment notice 20250596 of 1 April 2025, which ends the authorisation on 30 November 2027, allows sale of existing stocks until 31 May 2028 and use or disposal of what is left until 31 May 2029.
So the glyphosate-free bottle is the one with a date on it, and that is a genuinely useful thing to know before standardising on one. The wider approval question, which is a different argument with a different answer, is set out on whether glyphosate is banned in the UK.
What I buy instead of a Roundup bottle
Roundup is the name everyone knows, and a good part of what you pay is the name. The active and the loading here are the same; what differs is the cost of a litre of made-up spray.
What I’d use
Glyphosate concentrate, 360 g/L
Gallup Home & Garden Glyphosate Weedkiller (1 litre)
The one Gallup a homeowner can legally buy and use: a 1 litre glyphosate concentrate at 360 g/L, approved for home and garden use under MAPP 17672.
It is the same active, the same 360 g/L loading and the same isopropylamine salt as the professional Gallup XL, and its single label rate of 24 ml per litre of water is exactly the rate the professional labels reserve for perennial broad-leaved weeds. The difference between the two bottles is the authorisation printed on them, not the chemistry inside, and this is the side of that line you are allowed to stand on.
- Active ingredient
- Glyphosate, 360 g/L, as the isopropylamine salt
- Formulation
- Soluble concentrate you dilute yourself
- Approval
- MAPP 17672, labelled for use only as a home and garden weedkiller
- Mixing rate
- 24 ml per 1 litre of water, per the label
- Coverage
- 40 sq m per litre of made-up spray, so roughly 1,667 sq m per bottle
- Rainfast
- Rain within 6 hours may reduce effectiveness, per the label
- Size
- 1 litre of concentrate
Watch out for
- No measuring cap in the bottle. Check a cup arrives, or the dose is guesswork.
- One re-treatment a season, and it takes four weeks. Do not go again early.
- Not for lawns. It is non-selective and takes the grass too.
- Resellers dominate the listing, so check the label that arrives is Barclay.
- "Super strength" is keyword stacking. It is 360 g/L, same as professional Gallup XL.
That’s an affiliate link: buy through it and I earn a small commission at no extra cost to you. It doesn’t change what I recommend or what I say is wrong with it. More on how that works in the affiliate disclosure.
No brand pays for a mention here, and nothing on this page is a paid-for opinion. The card above is an affiliate link, so I earn a commission if you buy through it, at no extra cost to you. It buys no product a kinder write-up, which is why the watch-outs sit on the same card as the reasons to buy.
About this resource
I'm The Weed Guy, one bloke who is qualified to use professional weedkiller. Every active ingredient, concentration, MAPP number, authorisation holder and expiry date on this page came off HSE's own home garden and professional pesticide registers on 14 August 2026, queried product by product, and anyone can repeat the lookup at the HSE pesticides databases. The pack claims, coverage figures, rain windows and treatment limits are quoted from the manufacturer's own published product pages, read on the same day.
Where I could not verify something, it is not here. I could not match the retail Fast Action Path and Drive ready-to-use pack to a register entry, and the page says so rather than guessing. I have not run these products against each other in a test and I am not going to pretend otherwise, so there is no claim on this page that one Roundup outperformed another in my hands. What is here is what the register and the labels say.
Straight disclosure: nothing on this page is a paid-for opinion, no brand sponsors this site, and there are no product links on it at all. How the site makes its money is set out in full on the affiliate disclosure page.
Common questions
Does Roundup contain glyphosate?
That depends entirely which bottle you have, and two of the best sellers contain none at all. Roundup Fast Action, Tough, Optima+, Ultra and Stump Killer are all glyphosate, running from 7.2 g/L in the ready-to-use bottles to 360 g/L in Ultra. Roundup Weedkiller Total Optima and Roundup Weedkiller Path Optima are pelargonic acid at 43.1 g/L, and Roundup Speed Ultra is acetic acid at 60 g/L. There is a lawn line on a fourth and fifth chemistry again. So the honest answer to a question about "Roundup" is that the brand covers five different actives, and you cannot resolve it without reading the back of the pack or the MAPP number.
What is the difference between Roundup Total and Roundup Ultra?
Everything that matters, and the names point you the wrong way. Roundup Ultra Concentrate is 360 g/L glyphosate under MAPP 18850, a systemic that the plant carries down into its roots. Roundup Weedkiller Total Optima is 43.1 g/L pelargonic acid under MAPP 20721, a contact herbicide that destroys the tissue it lands on and travels nowhere. "Total" here describes what it is used on, meaning everything green rather than a lawn, not how far into the plant it gets. If you want the root dead, Ultra is the one and Total Optima is not.
Which Roundup is the strongest?
On glyphosate, Roundup Ultra Concentrate at 360 g/L, which is fifty times the concentration of the Fast Action trigger bottle and matches the professional ProActive exactly. But watch the trap in that question, because the biggest number in the whole Roundup range is 565.49 g/L, and it belongs to Roundup Total Optima Concentrate, which is pelargonic acid. That is a bigger figure attached to a herbicide that cannot reach a root at any concentration. Grams per litre only compare products sharing an active ingredient.
Is Roundup banned in the UK?
No. Every product named on this page was on HSE's register and legally on sale in August 2026. Two things do complicate the picture, and neither is a ban. First, every Great Britain amateur glyphosate Roundup currently shows a register expiry of 09/09/2099, which HSE's own note explains is an extension applied under Article 43 pending a regulatory decision rather than a real date. Second, the products with genuine end dates on the register are the ones with no glyphosate in them: the pelargonic bottles run to 01/06/2029 and Speed Ultra to 31/05/2029. The approval question itself is answered separately on the page about whether glyphosate is banned in the UK.
What are the instructions for Roundup weed killer?
There is no single set, and treating them as interchangeable is how people waste a bottle. Fast Action is ready mixed and allows one treatment a year, with rain inside six hours reducing how well it works. Ultra Concentrate is diluted and makes up to 100 spray litres from a 1 litre pack, covering up to 3,000 square metres. Optima+ makes up to 50 spray litres, covering up to 1,500. Total Optima and Path Optima allow four applications a year and want reapplying if it rains within three hours. Speed Ultra also allows four a year. Read the pack you actually bought, because the differences between these are not details.
Is Roundup ProActive better than the Roundup in the shops?
It is the same concentration as the strongest garden one, so no, not on strength. Roundup ProActive is 360 g/L glyphosate under MAPP 21225, held by Bayer CropScience and marked Professional on the register. Roundup Ultra Concentrate is also 360 g/L glyphosate and sits on the home garden register, where anyone can buy it. What ProActive really buys is a bigger pack, a professional label with its own approved uses, and a legal requirement, because a professional-use product may only be bought for and used by a certificate holder or someone working under their supervision. For a drive or a path, the amateur bottle is the same chemical at the same strength with none of the paperwork.
Why does Roundup Speed Ultra work so much faster than the others?
Because it is a completely different chemical doing a much shallower job. Speed Ultra is 60 g/L acetic acid, and the manufacturer says first visible results can appear within an hour. That is the plant tissue the spray physically touched being destroyed, which is fast and looks impressive. Glyphosate is slow precisely because it is being carried down inside the plant to the roots, which takes weeks rather than hours. So the speed you are paying for on that bottle is the speed of the damage you can see, not the speed of the kill.
Is a 5 litre Roundup better value than a 1 litre?
Only if you check what is in it first, because bottle size and strength are unrelated across this brand. The 5 litre packs on a DIY shelf are ready-to-use, which is a mostly-water format, while a 1 litre of Ultra Concentrate makes up to 100 spray litres. Put the coverage side by side and it gets stark: 1 litre of Path Optima treats up to 33 square metres, 1 litre of Ultra Concentrate treats up to 3,000. Roughly ninety times the ground out of the same size bottle, on the same shelf, under the same brand name.
Can I use Roundup Path Optima on my block paved drive?
Its own safety instructions say not to. The product is described for gravel areas, permeable paths, driveways, patios overlying soil and along fences, and it tells you not to apply it to impermeable hard surfaces such as asphalt, concrete, cobblestones, tarmac, paving and patios, or anywhere else with a high risk of run-off. A sealed block-paved drive is exactly that. So a bottle called Path, sold from the manufacturer's own Path, Patio and Drive category, is ruled out on a good many of the paths people buy it for. Read the run-off wording before you buy it for a drive.
Which Roundup do I need to kill weeds to the root?
One of the glyphosate ones, and the pack will not say so on the front. In the current range that means Fast Action or Tough if you want it ready mixed, Optima+ or Ultra if you are happy to dilute a concentrate, or Stump Killer for a cut tree stump. Anything with Optima in the name that is not Optima+ is pelargonic acid, and Speed Ultra is acetic acid. Both of those destroy the top growth and leave the root alive, which is why their own labels allow four goes a year while the glyphosate bottles allow one.