Addiction, Health, Behaviour Change | CGL

CGL BaSIS, Royal Borough of Greenwich

CGL BaSIS is a free and confidential drug and alcohol service for adults in Greenwich.

We work with those living, working or studying in Greenwich who use:

  • Cannabis
  • Cocaine and party drugs
  • New Psychoactive Substances (NPS- formerly ‘Legal Highs’)
  • Steroids
  • Alcohol, but non- dependant

We also work with people who take part in ‘Chemsex’.

We offer up to 12 weeks of one-to-one psycho-social support, including groups and promoting health and wellbeing, whether clients want to be abstinent, cut down and reduce to safer levels, or look at minimising harm and using more safely. We also offer free staff training and have a presence at community events.

How to contact us

We always welcome new clients, so please get in touch if you are interested in getting help from the service or you’d just like to ask some questions. Feel free to bring someone with you on your first visit.

We are based at Royal Arsenal Medical Centre, 21 Arsenal Way, London SE18 6TE. You can call us on 0203696 2640 or email us on


If you would like to refer yourself or someone else to the service you can call us or visit the service in person.

You can also complete our referral form in advance and bring it with you when you visit the service.

Word referral form

We provide:

  • One to one keyworking
  • Foundations of Recovery (structured program)
  • Groups: on and off site
  • Outreach and satellites
  • Training for front line staff and user group
  • Signposting to partner agencies
  • Auricular acupuncture
  • Late night clinic

Can’t make your appointment?

It’s really important that you let us know. Ideally please call us on 0203696 2640. You can also email us on

What do our service users say about us?

“I learned about my mental wellbeing and how to tackle problems that I felt were out of my hands- and I am now dealing with them”

BaSIS service user 

What's on?

BaSIS has daily groups at Royal Arsenal Practice including: acupuncture, smart recovery, emotional well-being, mindfulness, cannabis and alcohol, plus an off site allotment. Phone 0203696 2640 for details as groups can change.

Where can I go for further support?

We have several pop-up clinics that change sites, please call 0203696 2640 for details.

Royal Arsenal Medical Centre
21 Arsenal Way
SE18 6TE
United Kingdom

Monday: 9am - 5pm

Tuesday: 9am - 5pm

Wednesday: 9am - 9pm (sessions after 5pm are by appointment only)

Thursday: 9am - 5pm

Friday: 9am - 5pm

Saturday & Sunday: Closed

When we close at 5pm, the latest we can see clients is 4.30pm.