A lot of what people put in their body before bed has a direct, measurable effect on whether they dream, how vividly, and whether they remember any of it. Most of them are working against you.
If you are trying to remember your dreams, or become lucid inside them, then anything that suppresses REM sleep is working against you, and a few of the most common bedtime substances do exactly that. None of this is about telling you how to live. It is about knowing what the thing in your hand is doing to the last third of your night, the part where nearly all the dreaming happens.
Alcohol: the great REM thief
Alcohol is the clearest case, and the most misunderstood. It makes you fall asleep faster, which is why people think of it as a sleep aid. But it strongly suppresses REM in the first half of the night while it is being metabolized. You get more deep sleep early and far less dreaming.
Then the rebound hits. Once your body clears the alcohol, usually in the second half of the night, REM comes roaring back to make up for what it missed. This is why a few drinks can lead to fragmented, sweaty, oddly intense dreaming in the early morning hours, along with the 3 a.m. wake-ups. For dream recall and lucidity, alcohol is close to the worst thing you can do: it flattens the early night and then throws your REM into chaos when it returns.
THC: suppression now, rebound later
Cannabis, specifically THC, follows a similar pattern with a nastier tail. Regular THC use tends to suppress REM sleep. This is why heavy users often report that they "don't dream," or rarely remember dreaming. The REM is simply being held down.
Ask anyone who has quit cannabis after regular use about their dreams that first week. The answer is almost always the same: they came back, all at once, and they were overwhelming.The well-documented REM rebound of THC withdrawal
That rebound is the tell. When you stop, the suppressed REM returns with interest, and people commonly experience a stretch of unusually vivid, sometimes disturbing dreams for days to a couple of weeks. It is one of the most consistently reported withdrawal effects there is. CBD, worth noting, behaves differently from THC and does not appear to hit REM the same way, though the research there is younger.
Melatonin: a timer, not a dream switch
Melatonin is the one people most often misunderstand. It is not a sedative. It is a signal, the hormone your brain uses to tell your body that night has arrived. Taken correctly, its main job is shifting the timing of your sleep, which is why it helps with jet lag and delayed sleep schedules.
Its effect on dreams is real but indirect and, honestly, mixed in the research. Some people report more vivid dreams on melatonin. The most likely explanation is timing rather than any direct dream-boosting property: by nudging your sleep architecture and sometimes shortening the time to REM, it can put you in more or longer REM at points where you notice it. Dose matters more than people think. Most drugstore doses are far higher than the small amount, often well under a milligram, that actually mimics your body's natural signal. Megadosing does not make it work better. It just makes it more likely to leave you groggy.
A note on the supplement rabbit hole
You will find corners of the internet pushing galantamine, vitamin B6, and other compounds for lucid dreaming. Some of it has genuine early research behind it. Galantamine in particular showed real effects in a controlled LaBerge-led study. But these are pharmacologically active substances, not candy, and some interact badly with medications or conditions. None of this is medical advice, and supplements are barely regulated. If you are going to experiment with anything beyond your own sleep timing, talk to a doctor first. Boring advice, correct advice.
What actually helps
The unglamorous truth is that the best "dream enhancer" is undisturbed REM sleep, and the cheapest way to get more of it is to stop suppressing it. Skip the nightcap and the late THC. Keep a consistent sleep schedule so your REM cycles fall where they should. If you want to add a lever after that, the highest-yield one is not a pill at all, it is timing your awareness to land in the REM-rich back half of the night, which is exactly what the WBTB method is built to do. Fix the inputs first. Then optimize.