panther cap (amanita pantherina)are a bit more toxic than fly agaric mushrooms (amanita muscaria) because panther caps contain more muscarine (poisonous substance) than fly agaric (not much, meaning trace amounts, but enough to make your trip more uncomfortable, more hard on the body)...anyway these can be used, but just like fly agaric shrooms, it must be COMPLETELY dry before ingestion...
Why ? Because fly agaric and panther caps main active principles are ibotenic acid (mildly toxic and mildly psychoactive), muscazone (slightly psychoactive), and muscimol which is the most interesting stuff in it as it is "non" toxic and quite psychoactive (psychedelic)...when I say muscimol is non toxic I mean it's not more toxic than speed, but for sure speed is toxic. So the idea would be to ingest only muscimol without the ibotenic acid (which gives a toxic uncomfortable trip), and the good thing with completely drying the shrooms is that ibotenic acid (the one you don't want) turns into muscimol (the one you want!) during the drying process.
SO: never eat the fresh shrooms ! Always dry them completely before eating...I heard that boiling the fresh shrooms in water for a few hours would be an other efficient way to convert ibotenic acid into muscimol, if so this would be easier than drying them (these shrooms contain so much water than drying them can be uneasy), but better just dry them as I'm sure this method does work.
Note that the trip has nothing to do with psilocybian mushrooms (psilocybes...) as fly agaric and panther caps do not contain any psilocybin (the main active principle once the shrooms are dried is muscimol)
Also important: never use shrooms you collected near a highway or polluted areas as shrooms abasorb pollution just like sponges which could make you very very sick AND be careful not to pick the wrong shroom (some other species of amanita are deadly, luckly fly agaric and panther cap are easy to recognize: red with white points/brown with white point). If you're not 100% sure of what shroom you found just don't take it (better get a shroom hunting guide to be sure identifying it correctly).
Dosages (from erowid.org):
Dosage is for completely dried cap material only:
Oral Amanita muscaria Dosages
Light 1 - 5 g (1 medium cap)
Common 5 - 10 g (1 - 3 medium caps)
Strong 10 - 30 g (2 - 6 medium caps)
Personally I would start with 10-20g of dried amanita muscaria shroom cap at most...let's say I think there wouldn't be big risks with 15g, but if the dose is to high for you then the trip might be quite uncomfortable, if so you might be in some delirium so better have a sitter with you.
I guess amanita pantherina dosages would be similar, just a bit smaller as panther caps are said to be more toxic (these may induce convulsion while muscaria cannot).
Effects (from erowid.org):
Onset : 30 - 120 minutes
Peak : 1 - 2 hours
Duration : 5 - 10 hours (higher doses seem to last longer)
Normal After Effects : 1 - 5 hours
POSITIVE
-euphoria: feelings of peace and well being
-marked analgesia (pain relief)
-physical relaxation / dream state: (during the sedative effects) can be highly detailed, colorful, and have a great sense of clarity and lucidity. Some people describe these as being similar to Lucid Dreaming. Some describe them as Out of Body Experiences (OOBEs). As with normal dreams, the Amanita Dream State can consist of a wide variety of experiences.
-internal dialogue: some people report a strong sense of an internal discussion, a feeling of being able to think through personal issues. Others report a significant reduction of internal dialogue, sense of peacefulness, and internal quiet.
-synesthesia: is somewhat common, smelling words, tasting colors, etc.
-clarity: Often no interference with memory or logic: many report strong "clarity of thought" and "stillness of mind". Others report mild to strong confusion.
-internal focus: Difficulty in focusing concentration on external tasks. Increased focus on internal imagination, imagery, day dreams.
-sociability: Group interaction can become incoherent: "conversational weirdness", frequent changes in topic, "non-linear conversations"
-sexual feelings: Some people report increased sexual feelings, others report very unsexual emotional and sensual distance / coldness.
NEUTRAL
-sedative or sleepy effects. others report excitation and extreme energy bursts.
-changes in body perception: effects may include dramatic shifts in body perception and motor skills including perceived changes in size of body parts, increased strength, dizziness, clumsiness, change in proprioception.
-slightly blurred vision, watery eyes, runny nose.
-loss of Equilibrium
-pupil dilation, glassy eyed stare
NEGATIVE
-Mild to moderate to extreme nausea or stomach discomfort/cramps, increases with dosage.
-muscle twitching and trembling (not convulsions)
-increased salivation and perspiration.
So...there seem to be much more positive effects described than negative (only 3 negative side effects which don't sound that bad to me)...and positive effects look really nice & spiritual: amanita muscaria was the sacred mushroom of siberian shamans, the magic shroom of european witches and the sacred ritual drug "soma " from india! This makes me feel that these shrooms must have some great potential, as an entheogen of course, not as a recreational drug.
BUT remember: if you don't prepare them correctly, then you'll only get pretty nasty effects (let's say only the negatives+ delirium).
I think I'm going to give them a try this summer as these are easy to find in nature (also interested in trying pure muscimol but it's damn expensive).