We call ourselves a commercial stage bioelectronic medicine and wellness company. I'll explain the two different product lines we have in those categories. Most important thing I want you to know about is the ticker is ECOR. Don't forget it. There will be a test on the fine print after the presentation. Overview first. I believe only FDA-cleared non-invasive vagus nerve stimulator. This one is mine. I keep it in my pocket. The business has been growing nicely for the last couple of years. Our five-year CAGR is about 69%. The business model is solid with the slide says 80%. It's 85% gross margins. We're on track to do $25 million and change in revenue for the full year 2024. Lots of the incremental revenue or lots of leverage rather in the income statement.
I think I'll talk a little bit about that later on in the presentation. Big total addressable markets. Right now most of our business is in headache. But we've got a pipeline of additional prescription indications and a rapidly growing direct-to-consumer business proven management team. I don't know why they put that on the slide, but it's a clean structure. There's no debt. It's all straight common $14.5 million in cash and marketable securities. I don't know why they crossed out the star there. And no debt. This is our flagship product. We call it the gammaCore Sapphire. This is our proprietary non-invasive vagus nerve stimulation technology. We're FDA cleared for acute treatment and prevention of most forms of primary headache.
Migraine being the largest cohort, cluster headache where we have outstanding clinical differentiation in first-line therapy and then a longer list of indications that I have trouble pronouncing. So I'm not going to waste your time on that. Acute treatment means that I feel like I've got a headache coming on. I take it out of my pocket. There are two electrodes on the business end of the device. You find your vagus nerve which travels in the same sheath as the carotid artery. Turn it on and hold it in place for two minutes. It times out at two minutes. I don't get a lot of headaches, but when I do, I can usually abort my headache with a two-minute dose of energy. More is better.
So if two minutes doesn't work, you can turn it back on again, have a second, third, fourth, fifth dose of vagus nerve stimulation. This is not a drug, so you can do as many doses as you would like. It can be used multiple times per day, per month. That's acute treatment. Prevention is a little bit different protocol. We ask our patients to use the device twice a day. So think morning and afternoon. The pivotal data showed a statistically significant reduction in the number of headache days. For those patients who were consistent with that protocol, compliance is important. I don't brush my teeth every day either. So if you don't use it regularly you don't get that full prevention benefit. Why the vagus nerve? The vagus nerve travels up to the brain. It communicates with all of the organ systems within the body.
The headache response is based on how pain signals are processed in the brain. This technology is also known to down regulate inflammation. It's known to downr egulate the sympathetic nervous system, that fight or flight response that leads to anxiety and post-traumatic stress disorder. It up regulates the parasympathetic nervous system which can be involved in depression. So because of those multiple methods of action that gives us a very exciting pipeline of additional indications in the future. Most, well, not most but our largest customer today is the VA hospital system in the United States. If you participate in the VA hospital system, the therapy is free to patients. Doctor or nurse writes a prescription, we get a purchase order, we ship directly to that patient.
We have a customer service team that inservices or onboards that patient and we get paid directly by the hospital. Our second largest customer is the NHS, National Health Service in the United Kingdom representing about 10% of our revenue. Identical business model in the UK. They don't like me to say their name out loud but we went on formulary at the Kaiser Healthcare System earlier this year. Similar business model to what we're doing in the VA except that Kaiser members have deductibles and co-pays and so there is a certain amount of depending on the benefit plan that any member is on, there's a certain amount of out-of-pocket expense. We have another 7.5 million covered lives and headache through some of the regional Blues, Highmark in Pennsylvania.
In 2025 and 2026 we're going to use the data and experience that we've collected in the clinic-based healthcare systems, the VA Hospital and Kaiser and start to approach the usual suspects, the national and regional insurance companies and Medicare. At the beginning of 2023 we launched our Truvaga product line. Truvaga is a lower dose version of our gammaCore Sapphire. So this is prescription strength. Truvaga is offered direct to consumer and it's a less intense modality. Truvaga is a general wellness product that we market for stress, for quality of sleep, and for cognitive enhancement. You can go to the truvaga.com and hit the buy now button. Right now it's exclusively available through our e-commerce store. That was $500,000 of Truvaga revenue in the June 30 quarter. It's been growing at 200%-250%.
It's smaller revenue than our prescription products, but it's growing faster than our prescription products. TAC-STIM is a very, very specialized version of our technology. We didn't know it, but it turns out that DoD and specifically Air Force Research Laboratory has been looking at neurostimulation for what they call Human P erformance with a capital H capital P for many years now. They found our technology about 10 years ago and three years ago they approached us and said they wanted us to do a mil- spec version of the technology for deployment to active duty. We did that. That's a very lumpy business in terms of it comes in contracts for $100,000 and then it goes dry for a little while. We love that as a predicate for civilian crossover in the future.
And it's a very large total addressable market just in active duty military in the US and our NATO allies. So these are our three product lines. Prescription gammaCore that I keep in my pocket all the time. Truvaga for general wellness. Go to truvaga.com, buy many of them and then the TAC-STIM device which doubles as a weapon if you can throw it at the bad guys. This is our e-commerce storefront. Very important to me, the shop. Now, as I mentioned, it's been growing at 200%-250%. So it's a very exciting growth rate. Two metrics that I watch, one is the customer acquisition cost. The other is the return on advertising spend, which for the second quarter, the June 30 quarter was 3.25. In other words, for a dollar of advertising spend, we're generating $3.25 of revenue. That's very scalable.
So we're going to continue to invest in that. Most of our spending has gone to search and social media on Meta, on X, tinkering with TikTok as we move forward through the back half of this year to continue to drive growth. We're getting more aggressive with influencers. We're tinkering with some podcast advertising. The beauty of these e-commerce businesses is that you can do rapid A/B testing. You can find what works and emphasize it and rapidly move away from what isn't working. And the cash on cash cycle is amazing. Right. We get paid. We tap your credit card before we ship the product. So receivables are very small from that business. As I mentioned, the background on how we got to TAC-STIM. Air Force has published a little bit of their data. They are deploying for accelerated training, sustained attention, reduced fatigue, improved mood.
The Air Force has published data from the Defense Language Institute in Monterey, California. They published some data about pilots learning how to land a jet in a simulator. They've published some data about ISR specialists who are the folks who are flying drones in places that we're not supposed to know about. So it's very exciting for the active duty deployment and long term, it's even more exciting for civilian crossover to first responders and to a large group of folks who can benefit from sustained attention and reduced fatigue. Right. That's a lot of us coming back to our prescription pipeline. Headache. We're done doing clinical work. We have a huge database of thousands of patients in migraine and cluster headache. Quite a bit of data has been published about post-traumatic stress disorder. Most of that data was collected in the VA hospital system.
The FDA has given us breakthrough designation to treat post-traumatic stress disorder. We're working with the agency to get a label extension to PTSD. Because the data was collected in the VA hospital, they're already our biggest customer. We're starting to get off-label prescriptions for PTSD from behavioral health within the VA hospital system. Substance abuse. NIDA, National Institute on Drug Abuse, gave us an $8 million grant last year to fund a pivotal trial. That trial has started to enroll patients. The trial will complete enrollment early next year and read out. We'll submit to the FDA towards the end of 2025. That'll be a 2026 story. Some fascinating stuff going on in traumatic brain injury and concussion. There are trials enrolling patients in Parkinson's disease and acute stroke.
All of that is beyond the planning horizon, but we're very, very fortunate that it doesn't cost as much. All of these trials are investigator initiated trials that are funded by grants either in Europe or DARPA, DoD, VA hospital system or NIH. Lot of patents. Our fundamental patents go until at least 2032, 2033. So we still have a pretty healthy runway to protect our core business in vagus nerve stimulation. Some of the numbers that we're excited about. Let's see our guidance. Full year 2024 guidance of $22.5 million. No other full year guidance is $25 million and change. I think that's a typo on this slide. Oops. The June 30 print was $6.1 million. I know my September 30 numbers, but I can't tell you yet. So it'll be very nice growth over full year 2023, that 68%-70% growth for the whole fleet.
You know, our prescription business is much larger revenue dollars and that's been growing at the 70% rate. But as I mentioned, some of our other channels are growing much faster from a smaller base and we'll accelerate things as we go into 2025 and into 2026. This is 7/4 now of sequential revenue growth. I know my third quarter numbers, so it'll be 8/4 of sequential revenue growth. Cash used in operating activities. I hate to say we burned cash, but that's what this slide is meant to convey. On $6.1 million, we used $1.8 million. In the second quarter of 2024, our gross margins are 85%, maybe a little bit more. Our variable cost of sales, whether it's commissions in the prescription business or media spend in our consumer business runs at 25%-26%. So we model 30%.
And so the point being that for an incremental dollar of revenue, our contribution margin is 60%-65%. So there's a lot of leverage in the income statement now that we've gotten to critical mass in revenue for the business. Clean cap table, there's no debt. I need to point out the pre-funded warrants. So we have 6.5 million issued and outstanding shares. Two of our institutional investors chose to make a structured investment as a pre-funded warrant. Company gets the cash, the investor can exercise that warrant on 24 hours notice. The reason they do that is because they want to stay below a 10% ownership threshold. They're already 13G filers and there's something about their fund structure that says they can't explicitly own more than 10%. So that's why they invest in a PFW structure.
The warrants, 1.6 million warrants are in the money right now. The options are not and so those are likely to expire unexercised. I'm the CEO. Josh Lev has been with the company for about four years, but he was recently promoted to the CFO title. Peter Staats. We're very, very fortunate to have him. Peter is a board-certified anesthesiologist. He had a successful practice. He's had an even more successful academic career, Past President of the World Institute of Pain and the NANS Society. And he's founder, co-founder of this company and a few other companies. He's Chief Medical Officer of our company part time and Chief Medical Officer of Premier Pain Centers, which I think is the second largest chain of pain management clinics. So that's our story. The ticker is ECOR.
The business has been growing 70% for several years now and we're at a $25 million annual run rate. You can extrapolate into what that means for 2025. Gross margins are at 85%-86%. I'm very proud of that. We're keeping a lid on operating expenses. So we're going to cross over to be cash positive early next year and GAAP profitability will follow that. I think I hit all the high points. Did I say the tickers? ECOR. Thanks. Any questions? Looks like I have a few minutes. Yes, sir. In the back. Yes. No, I hate to, and even more so now that we're in this sort of small commercial stage. If our sales guys hear about new stuff, they get easily distracted. So we try to stay disciplined about not talking about the pipeline in public. Yes, sir.
Have you had interest in indirect channels, doing DTC on your own? Yes, but you know, it's a product that would have. Where you could offer that through a Costco or somebody that wanted to do it right away. How do you think about that?
So we're going to go live on Amazon in January or February. Amazon takes a healthy vig and so I want to keep an eye on that contribution margin that I am so proud of. We're going to hold off on brick and mortar because it takes cash and I want to get to cash positive and profitability before we look at brick and mortar. The standard brick and mortar business model is that we have to deploy, consign inventory. You get paid very slowly and cash is king these days. So I absolutely think that's going to be a viable channel in the future, especially as we look at civilian crossover from what the Air Force is doing. But not right now. Yes, sir.
How is this differentiated from all invasive devices?
Yeah, so, you know, I try not to give TENS technology that much. They don't rise to the level of competition in our mind. So TENS is a technology for those who aren't aware that's been available for a long time. It's on label for back pain, for lower back pain, for lower extremity pain. It's contraindicated for use on the head and neck. It's not labeled for headache, nor is there any data around it for use in headache. On the wellness side again, there's no data to support the use of TENS in the quality of sleep, in stress or in anxiety. The lack of data has never stopped anybody from successfully selling things. But we're trying to take the high road there of being the clinically studied, validated, scientifically studied and validated technology. Yes sir. It's all in the energy level.
Our prescription dose is roughly three and a half times the strength of the dose in the health and wellness product. The way I explain it to my mother-in-law is that when I had knee surgery they prescribed Motrin, which is 800 milligram ibuprofen covered by insurance. But you can go down to the corner bodega and get Advil, which is 200 milligram ibuprofen and take four pills. But you got to pay for it out of pocket. Yes, sir.
How is this product different than the TENS device?
Oh, I'm sorry if I missed that. So, electronically. The company, before my time, put a lot of effort into developing a waveform that would penetrate the skin to the right depth to energize the vagus nerve. A waveform? TENS devices tend to be a very simple square wave. Ours is a modified sine wave and it's in the patents. I'm not very good at explaining it personally and that does two things. It more specifically energizes the vagus nerve and it's a lot more comfortable when it delivers energy through the skin. Yes, sir. Channels.
How much of these are we currently occupying?
Yeah, great question. So in the VA hospital system we've dispensed about 6,500 handsets. There are 800,000 round numbers headache patients in the VA hospital system. So by that metric we're about not quite 1% penetrated. Another way to think about the VA hospital system is that there are 1,200 and change VA hospital facilities, most in the United States, some of them overseas. We are on contract in 160 of them. So by facility we're roughly 10% penetrated within Kaiser. We're just getting started. Yeah, it's showing up its feet on the street. It's nothing glamorous, it's grinding it out. Yes sir. Yeah. So we have roughly 40 million covered lives now between the VA hospital system, Kaiser about another 7.5 million through some of the smaller regional Blues and Highmark in Pennsylvania. That's not enough. It's not critical mass?
No, it will grow, just not as quickly as I would like. So we're going to use the experience and the data from our current channels and go to the big national insurance companies and make a case for why they should start to pick up coverage. The other thing that happens is just word of mouth. Right. Patients start to ask for it. You get stories in the media that talk about the benefits of a non drug headache treatment or a non drug PTSD treatment. Yes, sir.
We're out to get more VA hospitals and Kaiser and all the channels on board. What additional growth plans do you have? Would it be something like acquisition process or? Again, you said you can't talk about any new development, but is there anything else that you guys are looking at?
Yeah. So in our prescription business, the growth is going to come from more penetration of the VA hospital system. We're just getting started in the Kaiser Healthcare System. Post-traumatic stress disorder is an adjacent total addressable market that's going to become available to us in 2025. It's already starting to be available to us with off-label prescriptions. Beyond that, substance abuse is another very large total addressable market and that's with our existing product set in parallel. If we start to launch additional products which I'm not going to tell you about, it all helps. Yes, sir. Yes. Yeah, it says zeros, but I'm happy to keep chatting. So. What's that? Always, every time my stock goes down? Yes. Headache. So headache. Everybody's different but headache tends to be a chronic condition. Right. And everybody is different.
Some cluster headache sufferers go for weeks at a time with one headache, and others like me, I get a headache, you know, once a quarter. That's a great point. We've been studying, and we're FDA cleared as a standalone therapy, but also as an adjunctive therapy. So you can use vagus nerve stimulation with any of the other pharmaceuticals that are used in treating headache. And actually that's one of our strengths is for complicated patients, patients who have comorbidity with cardiovascular disease or diabetes or respiratory problems, you start having a whole lot of different medications, and you can safely use vagus nerve stimulation as opposed to adding a headache medication on top of all of your other polypharmacy issues. Yes, sir.
How long does the device last for?
Until you drop it or run it over. So.
So yeah, so the definition of the Medicare definition of durable medical equipment is a useful life of at least three years. So we had to demonstrate a useful life of at least three years. But in practice, I've had mine for five years. We get revenue every three months. Yeah. Yes. TAC-STIM. They actually ran one over with a tank to see if it would keep going.
Yeah, we are officially out of time. If there's any additional questions, we could take them outside. T hank you, guys.