But some of them have a plan for how to get round the government's new banning order.
Since the first counterculture store Alchemy was opened by hippie legend Lee Harris in West London's Portobello Road in 1972, head shops have become nearly as ubiquitous as Pizza Express.
There are hundreds of them dotted around the nation's high streets and side streets, selling a pick 'n' mix menu of anything from fairy orbs and salvia, to Tibetan singing bowls and Exodus Damnation. They have been joined by a growing number of mainstream shops – such as takeaways, tattoo parlours, petrol stations and newsagents – whose struggling owners have decided to keep the wolf from the door with a lucrative sideline in new psychoactive substances (NPS).
But soon, maybe before the next election in 2015, many of these places will have vanished and become betting shops and mini Tescos.
On the 30th of October, the government announced it had accepted the recommendation of a panel of experts to introduce a blanket ban on everything that gets you high, prohibiting the distribution, supply, importation and exportation of all psychoactive substances. Tobacco, alcohol, coffee and psychoactive medicines, those deadly drugs that Britain holds so close to its bosom, will be exempt from the ban.
The primary target of this proposed new law are the shops selling legal highs. These outlets have caused huge embarrassment for police, trading standards, local councils and the government. The media has had a field day mocking their inability to stop shops selling potent and potentially lethal synthetic cannabinoids and stimulant powders and pills. Drug services have pointed out that these shops make it as easy as falling off a log for children, the homeless and those with mental health problems to buy what can be highly potent, addictive and unpredictable substances.
Under the plans, shop owners caught selling drugs will face large fines, prison and have their premises shut down. Importantly, there will be no burden of proof, meaning that the wheeze of putting "not for human consumption" on packets will give sellers no protection. If a product looks like it might give you jazz eyeballs for even one second, the cops will incinerate it. As Norman Baker, the Lib Dem drug minister who has since resigned, proudly informed fellow MPs at the launch of the report: "The head shops could be left with nothing to sell but Rizla papers."
For some of Britain's head shop owners, the plans represent the final round in the ding-dong battle between the authorities and shops' right to sell psychoactive substances that has been going on for decades.
Elliott, a family man with kids and a mortgage, has run a head shop on the south coast since 2000. He told me that "leisure products" [legal highs] have been a crucial part of his business for the last 14 years. "First of all we sold herbal highs and that was 20 percent of the business. Then magic mushrooms kicked off and I made a bomb selling them and the growing kits. I took 60 kilos of mushrooms to Glastonbury one year. It was 60 percent of my business.
"Yes, the government strangled mushrooms, but within six months BZP arrived. It was a good thing for head shops; it made us lots of money. And when BZP was banned in 2009, along came Spice. As soon as I smoked some I knew it would sell; I had to employ two extra members of staff because I did so well out of Spice and all the new pills and powders."
But Elliott, who sells his drugs discreetly and does not advertise because he doesn't want the heat of the teenage trade, says the end of the road is in sight for most outlets. "Those guys who come round with bouncers selling all this stuff to all the legal high shops will have to find something else to do. The blanket ban will be the nail in the coffin for a lot of places who sell legal highs," says Elliott, who estimates there are at least 500 shops selling NPS in the UK.
For a vision of the future look no further than Ireland, where a law – on which the UK plans are modelled – has virtually wiped out the head shop trade.
The Irish government got in early with its anti-legal high and head shop laws, because they were upsetting the delicate drug ecosystem. Shops were being petrol bombed by drug dealers, or "community leaders" as they like to call themselves, who saw them as competition. Something had to be done and the upshot was the Irish Criminal Justice (Psychoactive Substances) Act.
"Those guys who come round with bouncers selling all this stuff to all the legal high shops will have to find something else to do. The blanket ban will be the nail in the coffin for a lot of places who sell legal highs"
By the time the law came into force, most of the country's 113 NPS outlets, with a bit of help from bullying Garda officers, had shut their doors. Most decided to throw in the towel either because they had criminal connections, such as money laundering or links to mobile phone fencing, or simply because, as their tax returns later proved, they were so reliant on NPS drug sales that their business would have collapsed without the income. Garda officers seized 4.5 tons of NPS. The battle was also fought online, with the closing down of all online head shops with an Irish IP address.
Four years later, and only a handful – 20 at most across Ireland – have stubbornly survived, managing to maintain their businesses by selling legal products such as cannabis seeds, bongs, hemp pyjamas and Bob Marley T-shirts.
Research into the impact of the law – carried out by drug experts Tim Bingham and Fiona Measham, and due to be published next year – has found that much of the trade in NPS has simply been displaced to street dealers and online purchases. When the Garda closed down all NPS sites with an Irish IP address, they simply re-opened with a UK address. Researchers have also found that some drug users have reported using illegal drugs, such as heroin, ecstasy and speed instead of legal highs.
The law has reduced the number of people getting into problems with these drugs – the numbers of people entering drug and mental health services for NPS problems has fallen. However, the desire for cheap synthetic cannabinoids and analogue stimulants in the general population remains undiminished by the head shop cull. Stats from the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) show that, between 2011 and 2014, after Spain, Ireland saw the second largest increase in young legal high users in Europe.
One head shop owner in Dublin, who has been involved in the industry for a decade, told me she had remained open out of principle and because she specialises in medical herbs such as St John's wort. "When the law came in and the heat was on, most shops closed because they were either run by gangsters who never paid taxes or they never had the balls to stand up to the police," she tells me.
Her shops have been raided, with Garda seizing her products, 12 times since 2010. So why does she bother? "My business is family run, it's my life and it's in my blood. I enjoy the people I work with, the customers and someone's got to provide a counterbalance to what Monsanto is doing. The blanket ban is a load of bollocks. In my book it's better to face a problem than sweep it under the carpet, because otherwise you just leave it in the hands of unscrupulous people."
It's clear the new laws in the UK will result in the mass closure of the more fly-by-night NPS outlets, with the old school head shops having the best chance of remaining. But for Elliott, on the south coast, after mushrooms, BZP and new psychoactive drugs, there is a new lifeline – vaping.
"E-cigarettes is the new emerging market. I've anticipated the fact NPS would be banned and I've already got them in the shop and they are good sellers. Any head shop owners with their head screwed on will do the same, because you can't rely on all that hippie stuff like bongs and pipes; it's a dead market. Cannabis seeds have always been a good seller, but vaping is the future."
Ever since the floodgates to the modern online drug trade in new psychoactive drugs were blasted open by the Great Mephedrone Explosion in England in 2009, authorities around the world have been battling to slam them shut.
But the authorities know they cannot ban their way out of this problem. They know, like in Ireland, drug users will just buy off street dealers or online. Underground dens, possibly selling cannabis E-cigs, may pop up once the laws come in (the timing of which depends on whether David Cameron sees head shop clampdown as being a vote-winner). For the government, it's seen to be doing its job: fighting the drug trade in its most visible form, in the hope that if it stays behind closed doors, it will seem less real.
Follow Max on Twitter @narcomania
Previously in this column – Cutting Through the Bullshit About the 'UK Crystal Meth Boom'