LiBBY Study: What Families Should Know About THC/CBD for Dementia Agitation

Anyone who has cared for a person with advanced dementia knows how hard agitation can be to watch. A new federally funded study found that one specific THC/CBD oil helped reduce it. The catch is that this oil is not sold in Florida dispensaries or anywhere else, so families cannot recreate it by buying a similar product.

What is dementia?

Dementia is not one disease. It is an umbrella term for a decline in memory, thinking and daily abilities that gets in the way of everyday life. Alzheimer’s disease is the most common cause, and others include vascular dementia, Lewy body dementia and frontotemporal dementia. It is progressive, so in the late stages many people need help with eating, walking and personal care, and often lose the ability to speak clearly.

When the words are gone, behavior often becomes the way a person communicates. Agitation is one of the most common and hardest symptoms for families to live with. It can look like pacing, calling out, moaning, fidgeting, repeating phrases, verbal hostility, or hitting, kicking and pushing. Researchers describe it as often being a signal of pain, fear or an unmet need. The LiBBY team says agitation affects about half of people with dementia near the end of life.

How agitation is usually treated

1. Look for a cause and change the environment. Pain, infection, constipation, hunger, noise and changes in routine can all trigger agitation. The Alzheimer’s Association recommends non-drug steps first: a calmer setting, structured routines and psychosocial approaches.
2. Medicines for memory do not target agitation. Donepezil, rivastigmine and galantamine, and memantine for moderate to severe disease, are symptom treatments. They are not cures, and they are not aimed at behavior.
3. Medicines for agitation. Brexpiprazole (Rexulti), an antipsychotic, was approved by the FDA in 2023 for agitation in dementia. Like other antipsychotics, it carries the FDA’s most serious warning, a boxed warning about an increased risk of death in older adults with dementia. Doctors also use other antipsychotics, benzodiazepines (such as Valium) and opioids off-label, meaning the drug is not approved for this use. These can cause sedation, falls and other side effects in frail patients.
4. Many families are left without a good answer. The LiBBY team reports that more than one-third of people with end-of-life agitation continue to have symptoms despite those off-label medicines.

Why researchers looked at THC and CBD

THC and CBD are two compounds from the cannabis plant. THC is the part that can cause a high. CBD does not, and it can soften some of THC’s effects. The LiBBY team notes that both act on brain systems tied to emotion, anxiety, sleep and pain, which is the reason for testing them together on agitation.

Earlier evidence was limited. A small placebo-controlled crossover trial of nabilone, a lab-made THC-like drug, helped on an agitation scale but showed only a trend on the overall rating. LiBBY is the first randomized, placebo-controlled trial of purified THC and CBD in hospice-eligible people with dementia.

What the study tested

The LiBBY trial (Life’s End Benefits of Cannabidiol and Tetrahydrocannabinol) was a 12-week, phase 2 study in 120 people with Alzheimer’s disease or another dementia who were eligible for hospice or already receiving it, and who had significant agitation. It was funded by the National Institute on Aging and run through the Alzheimer’s Clinical Trials Consortium. Results were presented July 14, 2026 at the Alzheimer’s Association International Conference. At the time of writing, no peer-reviewed journal paper had been found, so the figures here come from the study team’s presentation and results page.

• Design: randomized, double-blind, placebo-controlled. Neither families, clinicians nor researchers knew who got the oil and who got placebo.
• Who took part: average age 80, 55% female, 45% Hispanic or Latino. 75% lived at home in a house or apartment. Caregivers gave the doses.
• The product: a custom oil called T2:C100, made in Canada by MediPharm Labs. Each 1 mL contains 2 mg THC and 100 mg CBD, a ratio of 1 part THC to 50 parts CBD. People with sesame oil sensitivity were excluded.
• The dose: week 1 was 1 mL twice a day (2 mg THC and 100 mg CBD per dose). From week 2 through week 12 it was 2 mL twice a day (4 mg THC and 200 mg CBD per dose), for a daily total of 8 mg THC and 400 mg CBD.
• How agitation was measured: caregivers rated 29 behaviors, such as pacing, calling out, hitting or kicking, on the Cohen-Mansfield Agitation Inventory. Clinicians also gave an overall rating of whether behavior had improved.

What it found

Agitation dropped faster and further on the THC/CBD oil than on placebo, and the gap held for the full 12 weeks. The study met its main goal and all its key secondary goals.

• Week 2 (main goal): agitation scores fell 6.27 points more on the oil than on placebo (95% confidence interval 2.87 to 9.66 points, p = 0.0004).
• Week 12: the average gap was 8.23 points in favor of the oil (95% confidence interval 4.86 to 11.6 points, p < 0.0001).
• Clinician overall rating at week 2: behavior was rated improved in 83.9% of people on the oil and 30.5% on placebo.
• Clinician overall rating at week 12: 87.2% on the oil and 23.6% on placebo.

Two things help put the headline “nearly 9 in 10” in context. It is the clinician’s overall rating of improvement, not a cure, and nearly a quarter to a third of people on placebo were rated improved too. Also, 16 of 61 people on the oil and 6 of 59 on placebo stopped treatment before week 12 (26.2% vs 10.2%), mostly because of death or being unable to continue.

Safety: what families should know

Most side effects looked alike in both groups, but serious events and deaths were more common on the oil. The investigators judged that none of the serious events or deaths were related to the study medication, and they found no pattern in the causes of death. The trial was small and cannot settle the question, and the research team itself lists the higher number of deaths among its conclusions.

The people in this trial were very frail and hospice-eligible, so illness and death were expected in both groups. Even so, the higher number of serious infections and deaths on the oil is something families should talk through with a physician.

Key points for patients and caregivers

• Real signal, early evidence. This is the first randomized, placebo-controlled trial of THC and CBD in hospice-eligible people with dementia. It was a phase 2 study of 120 people, and the researchers plan a larger one.
• It tested one product only. The results apply to the T2:C100 oil at the dose and delivery used in the study. The study team states they do not apply to any other cannabis or marijuana product.
• The oil was mostly CBD. The ratio was 1 part THC to 50 parts CBD, and the daily THC total was 8 mg.
• It worked fast. The difference from placebo was clear by week 2 and held through week 12.
• Serious events were more common on the oil. That includes infections and deaths. The investigators judged them unrelated to the oil, but the trial cannot rule out a risk.
• Non-drug care still comes first. The Alzheimer’s Association recommends environmental changes, structured routines and psychosocial approaches as the first step for agitation, and individualized decisions made with the care team.
• Do not substitute on your own. Dispensary products vary in ingredients, quality and dose, and the researchers warn they may be ineffective or even harmful for this population.

Can you buy this at a Florida dispensary?

No. No Florida dispensary carries the LiBBY oil, because it is not sold anywhere. The study team describes T2:C100 as a formulation they designed, made in Canada by MediPharm Labs, that is not publicly available and not used for any other purpose. They also warn that dispensary and online THC/CBD products may differ widely in ingredients, quality and dose.

Many families ask whether something close is on the shelf. No Florida product was found that matches the study oil, which has 50 parts CBD for every 1 part THC. The nearest widely listed option that could be verified is a CBD-dominant tincture from Curaleaf, which has noticeably more THC relative to CBD. The table lines them up as the THC that comes with every 100 mg of CBD. It is a comparison, not a dosing guide.

The Curaleaf tincture has about 3.3 times as much THC for the same amount of CBD as the study oil. Its online menu listing showed pickup at Curaleaf Port Orange, Cutler Bay and Wellington, with five more locations hidden, at $45 a bottle. The page also says content varies by harvest.

Watch the labels closely, because brands write ratios in different orders. Curaleaf writes THC:CBD, while Trulieve’s TruNano listings write CBD:THC (for example 8:1 CBD:THC, 250 mg total, though the exact milligrams could not be confirmed). Always read the milligrams of THC and CBD on the label, not the ratio.

What may change next

Standardized products. The LiBBY team plans a larger study. If larger studies confirm the results, it is an open question whether Florida’s licensed medical cannabis operators, who already make CBD-dominant tinctures, could someday produce a standardized low-THC, high-CBD product like the study oil. Until a product is made and tested to that standard, a dispensary version would not have the evidence behind LiBBY.

A new federal hemp law. A federal law adopted in November 2025 redefines hemp. Products with more than 0.4 mg of total THC per container would no longer count as hemp, and law firm analyses say this includes full-spectrum CBD products. Most of the changes were delayed from November 12 to December 11, 2026 by a stopgap funding law, H.R. 6500, signed September 2, 2026. Congress could still pass a regulatory framework or another delay before then. If the law takes effect as written, full-spectrum hemp CBD sold outside dispensaries may become much harder to find. The sources reviewed for this post do not say how it affects state-licensed medical dispensary products or CBD products with no THC.

Questions to ask your care team

• Is agitation the main problem, and have we tried non-drug approaches such as routine, environment changes and checking for pain, infection or constipation?
• What medicines is my loved one taking now, including antipsychotics, benzodiazepines and opioids, and could a THC or CBD product interact with them?
• Given the higher number of serious infections and deaths in the LiBBY oil group, what should we watch for?
• Who will give each dose, and how will we track agitation, sleepiness and falls?
• If we use a Florida dispensary product, which exact label amounts of THC and CBD are appropriate, and when do we review it?
• Is my loved one eligible for a future trial? The Alzheimer’s Association runs a free matching service at trialmatch.alz.org.

Sources